Although I can't recommend a place since I was there for a short period of time, there are many hotels that are worth staying at.
The Hilton, of course, is a safe bet because it's a chain and has standards.
Kapok Hotel is not a chain and is local, but I've heard it is excellent, and it is downtown, where you can easily access all the other ex-pat stuff if that's your thing!
There's also the Crowne Plaza in town that isn't too shabby. It is definitely downtown-not bad.