I live in Pattaya and going to Bangkok for business a few times a Year.
Favorite Hotels are:
* The Davis (Sukhumvit Soi 24)
Pro: Good Sized Rooms.
Have Rooms for Smokers
Usually about 60-70 US$
Con: A bit away from the Bar Areas, one km from Sukhumvit Rd. Not too many Restaurants in the vicinity
* Moevenpick Sukhumvit
Pro: Nice designed Rooms. Great Restaurants at decent prices.
Have Rooms for Smokers
Great Sukhumvit Location Soi 15, close to everything.
Con: Sometimes the price goes up to more than 100$. But often can be had for about 70 - 80