I like the Rambuttri Village. It's on Soi Rambuttri, which is near Khao San, but not so much right in the middle of things. This place feels kind of like a hotel, which really nice, clean rooms, but it's no more expensive than the rest of the places in the area, and there are tons of travelers staying there all the time.

I think there are a few in the Siam area that are nice, quite chill, reasonably priced.