Anonymous participant Of course, if you want to explore these towns, it would make sense to catch a bus only to the first destination.
Nong Khai is nice, but might be more convenient to head directly to Udon Thani on the international bus, explore a bit then fly out (since the airport is located there; there's no airport in Nong Khai).
I've crossed into and out of Thailand through nearly every land border checkpoint the country shares with it's neighbors.
The only ones I haven't tried are the borders between Narathiwat/Yala and Malaysia, as they're located in dodgy areas, with the security situation on the Thai side quite worrying.
I also haven't tried the Phayao and Beung Kan crossings with Laos (though I've been to both, just haven't actually crossed over). I am sure I'll be crossing those in the relatively near future, especially once the new bridge in Beung Kan opens next year.
Anonymous participant Yes and a Thai 5 year license is not only fine for both (especially Laos) the IDP isn't required. However, for Phnom Penh, it's highly recommended otherwise, you could be fined.
This is not an exhaustive list, but here are some good/not so good land borders (in my experience):
Nong Khai: efficient, rarely any questions (very occasionally, you'll get a chatty and friendly officer, but only if you speak Thai. If you don't speak Thai, you're nothing special and they'll just stamp you in).
Mukdahan: efficient, rarely any questions asked. Some officers not so friendly, they want things done by the book, so follow their rules.
Chong Mek: good and friendly (if you use the entrance lanes for cars; less friendly in the lanes for passengers)
Ranong: they'll want you to show 20,000 Baht and might even ask you for an outbound plane ticket and accommodation before admitting you or even stamping you out. You need to (politely) insist that all of this isn't necessary (if you're on a multiple entry visa). Or show them the 20K only, which usually satisfies them. You can talk your way out of these, if you speak Thai and explain your situation.
Wang Prachan, Satun: officers will assume you're a border runner and will go through your passport carefully, but then stamp you in without even talking to you.
Sadao: I haven't entered there in recent years, only departed that way (several times over the past 2 years), but I understand it's the same as in Wang Prachan.
Aranyaprathet: Using the entrance for vehicles, it's fine but only if you're traveling alone and are the driver. If you have to go to the immigration hall, you'll be dealing with Thailand's strictest immigration officials. In theory, DTV holders should be OK but I'm sure they won't accept same day re-entries here. This border has a reputation for refusing entry to foreigners.
Hat Lek: efficient, won't really talk to you but never a problem re-entering.
Yep. Anyway, so just to be a little more specific: first entry (via the airport) a couple of questions, nothing overly intrusive, good experience.
Second entry (by land): zero questions (which is usual at that particular border).
I find that certain land borders have chatty officials, others are known for being efficient but they won't ask you anything. Others still can be more intrusive and/or ask a lot of questions.