Keep in mind that sidewalks are very crowded in BKK. A walk of a few blocks can take quite a bit longer than you think.

As to where to stay, lets have an honest moment. If you're going to Bangkok for partying and women, you'll want to stay somewhere along Sukhumvit. There are a variety of Marriott and Starwood properties over a 3.5 mile stretch of the street. Pick a property that's close to where you want to go and/or close to the Skytrain and/or the MRT.