Cambodia
If you exclude things like DisneySea in Tokyo and the Great Wall of China in Beijing--because how do you seriously compete with things like those--Cambodia was probably one of the best vacation experiences I've ever had.
First, the cultural experience alone is completely fascinating. The countryside scenes feel like a whole other world, a vision most people will probably only ever seen on television or in movies but still not really grasp just what it's like until they see if first hand. But then you get into Siem Reap which is a whole other kind of fascinating. It's the capitol city of the Siem Reap province, but it only has roughly 175,000 people (the province as a whole has something like 900,000). It's a place that's hard to describe. The city is small with no big buildings and looks a bit run down. But the closer you get to the center of the city, the more vibrant and westernized it gets. This is basically the French Quarter of town, hopping with tourists (I seriously saw more white people in Siem Reap than almost anywhere else combined within the last year. This place is a serious tourism hot spot). And I've already described numerous times what the streets and transportation looks like.
Again, the people here are ridiculously kind, friendly, pleasant, and any other positive adjective you could give their personalities. Even if they had some ulterior motives, like trying to score some extra cash in varying degrees (excessive offers for Tuk Tuks, massages, and prostitutes at the top of the list), they would do so in the friendliest possible ways. With only one exception that I found (the massage girls in the back road), nobody was aggressive or rude. Also, almost all Cambodians seem to speak English. I never once found myself in a situation where I couldn't communicate. Every single person I came across spoke relatively fluent English.
Around November, when I started making plans for the trip, I contacted Mr. Sam's Tuk Tuk about basically chauffeuring me during my trip. He also had set packages and prices for different places and things to see/do. We spoke on and off for the last 4 months. When it came into the last couple weeks before the trip, he started sending me emails about possible changes to the itinerary. He had some personal obligations come up, and he kept me updated on the situations. Things flip-flopped for a while, but I appreciated that he kept me in the loop the whole time and was completely intent on helping me have the best possible trip. He hired a personal tour guide and had a friend act as driver for the first day of the tour since he couldn't be there. But then the second day it was him and the same guide. And both were wonderful. I would fully endorse using Mr. Sam if you were to ever come here.
I also fully endorse using the place I stayed--The Golden Temple Villa. The staff was absurd in how welcoming, positive, helpful, etc., they were. I mean, even the cleaning ladies seems to be having a good time when I came back the one day, and they were cleaning. They acknowledged you every time they saw you. And if it's your birthday while you're here, they will even come to your room and sing you happy birthday (I heard them do so to a guy down the hall--not sure if anything else came with it the song, since they were there for at least 5 minutes chatting afterwards). And they give you two free bottles of water daily (since you can't drink from the tap). They also give you a farewell bottle of water and a gift scarf, as well as take a picture with you, which they emailed to me later. For 3 nights, I only paid $45 bucks, and everything was perfectly serviceable for that price. Keep in mind, though, it's not a hotel. It's more a guest house. The room was a decent size. There was only one outlet I could find, and it was in an awkward place. Your room kept very cool (cold even). The bathroom dried quickly after a shower. And, even more importantly, the restaurant food was actually quite good, especially for the price. It's also in a fantastic location close to many good areas, though your Tuk Tuk drivers might not be able to find it on the first go.
All in all, if you can stand to be covered in sweat for however long you'd visit (minus the times you're in your room), I strongly recommend checking out Cambodia. It's a beautiful albeit very poor country filled with fascinating culture at every turn. Everything is priced really cheap. The food is good. The people are great. There was very, very little to dislike about this trip. If you're interested in different cultures and could choose only one place in Southeast Asia to visit (and don't want to go to China and/or the Great Wall), come to Siem Reap, Cambodia.
Thailand
Despite the fact I only stayed in Thailand a day longer than in Cambodia, it feels like a lifetime ago that I was there... mostly because so much seemed to happen in Thailand. I would rank Thailand along the same lines as my Beijing trip, but with much nicer people (which makes all the difference). The temples and palaces were all pretty cool and interesting, but as time goes by, they kinda blend together. Even doing my write-ups, I had to double check which things happened where and in what order. Don't get me wrong--they're all pretty stunning to look at and be amongst. But over the last year, I've seen so many temples and palaces and mythological spirit animals and Buddhas that my brain starts to melt after a while. I think that's why I liked Cambodia so much, because its temples and palaces were so different to the other ones I've seen. (Though the long-tail boat trip down the Bangkok canals was rather unique and pretty cool.)
That being said, what made it all worth it and infinitely more interesting and entertaining than it might have otherwise was my tour guide, Pepsi. I went through the website Travel Hub (who are a bit pricey for a solo traveler, but whatever), and Pepsi was the guide they gave me. I've raved about him before, but let me say it again... the guy is pretty dang personable, like you're just hanging out with a friend rather than some guy who is just doing a job and moving you along from one place to the next. Though I did keep hearing that in the years he's done this job, I'm one of the very few (like less than 3) he's even done that was solo. Most are families or big groups. So that might have had something to do with it. Still, no matter where we were--temple, palace, or otherwise--he made it fun.
There was one day I had without him, though, which was my birthday when I saw the Siam Niramit show. And that whole thing was pretty cool. It's about 80 minutes long and gives you a brief look into the history, culture, and mythology of Thailand... all in the single most stunning stage performance I've ever seen. They did things on that stage I still can't describe, and the parts I can were so grand in scale that you just have to see it to believe it. If you're ever in Bangkok, this is easily the one thing not to miss.
However, I'd honestly say the most memorable stuff of my Thai trip happened outside of Bangkok in Kanchanaburi. From going down a river in the rain to being at the Bridge on the River Kwai to riding a train down the Burma Railway (and then having said train die right near the end point)... it was all really cool and definitely memorable. That final day, though... Erawan National Park and Tiger Temple are really, really cool (in the awesome sense, because it was exhaustingly hot that day). If you ever go to Thailand, I would strongly suggest checking out these places... and bring your swimsuit for Erawan. I think my biggest regret of the trip was not swimming there.
In fact, whereas I feel maybe 3-5 days is perfect for Siem Reap/Cambodia, I'd say 2 weeks is probably a good amount of time for Thailand. The first week should be Bangkok, Kanchanaburi, and Chiang Mai (which I didn't go to). You can easily do Bangkok and Kanchanaburi in 4 days and then head to Chiang Mai for another 2-3 days. And the second week should be the islands and beaches (which I also didn't go to).
The people in Thailand are nice, but there was also sometimes a sense that they're just doing their job (there were some exceptions to this, the main ones being Pepsi and anyone he encountered that he knew, as he seems to bring out the best in people). But for example, the workers at my guest house in Bangkok (which I'll get to in a minute) were kind, but there was a type of blankness to them, like they were going through the motions. Even when they sang me happy birthday, you could tell they just wanted it to be over as soon as possible so they could go back to their corner and hide away. All in all, though, I never met any rude people that I can think of. There was, though, a considerable decline between Cambodia and Thailand in how many people could speak English and how well. Even Pepsi wasn't completely fluent, and I had to word a few things carefully when I tried to explain something. Strangely, the only issues the language barrier gave me in Thailand was when I tried to show directions in Thai. This just confused cabbies, especially the one who couldn't read his own language.
The two guest houses I stayed at were nice. The first was Phranakorn Nornlen, which is a place pretty difficult to find as you have to travel down a couple different alleyways to get to it. But the design and layout of the place is fantastic. You'll forget that you're actually in the middle of a bustling metropolis. And it had pretty much anything you could ask for. If you're looking for high quality at a cheap price and don't mind being a bit out of the way to get there, this is a solid place to choose. The hotel in Kanchanaburi was actually the only true hotel I stayed at the entire trip, and there was that noticeable escalation in shininess and artificiality that comes with hotels over the quaintness of the guest houses. It was called Sabai@Kan, and it was still a really nice place. I can't tell you to what degree as I stayed there less than 24 hours. But in the time I did spend there, it seemed really clean, nice, and pleasant, and with a legitimately friendly staff and good food.
So really, Thailand was a mixed bag for me. None of it was a negative experience (except the heat, but that was to be expected. And also Bangkok traffic, which was a nightmare). I would recommend checking it out if you're interested in going, but I also recommend putting more focus on things like Kanchanaburi or the beaches than Bangkok. Bangkok isn't bad, and there's definitely some worthwhile things to do there, but you can knock most of the big stuff out in a day and a half to two days (major temples and palaces in the morning and Siam Niramit at night... boom--the essentials done).
Special Note
I did want to bring up one more thing that I didn't talk about much in my blog posts, because I didn't want to put much worry on people reading. And that's the current Bangkok Anti-Government Protests. The presence was definitely there throughout the city. There were signs and notes to tourists and travelers all over the place. Traffic is apparently normally terrible in Bangkok, but it was made infinitely worse by the protesters. The first time going into the city toward my guest house, my driver and I passed at least a couple hundred cops in full riot gear preparing to go down and deal with the protesters. And that same day, soon after that, one of those cops (I presume) made some big news. A protester threw a grenade at the wall of cops. The officer tried to kick the grenade away to save his fellow officers, but in the process got his legs nearly blown off. He was in stable condition last I read, but of course his legs were pretty badly injured. Now, I never saw any of the protests, nor was I ever in any danger. But you could still definitely feel it all in the vibe of the city. Had it not been for the protests, I might have ventured out more on my own. But with my habit of getting lost, I was a bit more wary to do so. Still, despite everything, I'm not upset I went to Bangkok... and I can now even say I was there during these events!
Conclusion
I guess to wrap things up, I'll say that I'm really glad I went to Cambodia. It wasn't even on my radar when I was thinking about trips I could take during my stay in Korea. I just happened to come across the idea by chance after the Philippines were hit with that typhoon. And it was probably the best choice I'd made. Such a cultural experience, far beyond my expectations. Thailand, while not equally fascinating, was still definitely a worthwhile trip. There was some gorgeous scenery and some fun events, and I even got to touch some tigers! But I think if I ever go back, my itinerary would be quite a bit different (and if I had to do it all over again... I'd still do the same things, but I'd give myself more time to be there to experience a couple more places, like anywhere with water). It was a great trip all around, and I'm glad I took it.