I like Bangkok, but what do you consider "reasonable"?
Centerpoint Terminal 21, is a nice hotel, and not too pricy, I spent a couple weeks there over Christmas and New Years a few years ago and it was great. The room had a kitchen and a washer-dryer, and connects to Terminal 21 the BTS and MRT, and easy walk to Soi Cowboy.
I also really like Novotel Siam Square, and have stayed there countless times over the years. Great location, plenty to see and right next to BTS station Siam.
The Landmark is nice, and an easy walk to Nana Plaza it what you really want is a gash-fest.
I would not worry about doing tourist stuff like the dinner cruises and whatnot, because you can typically book these with transportation that will pick you up at the hotel.