If your looking for someplace different and by different I mean strange and eclectic give Tuba a try. It's one of the strangest designed places that I have ever been to. The art work consists of antiques, some quite strange (think Addams family) and unique items strangely displayed. The seating unconventional; sofas, lounge chairs and easy chairs. The food is not bad and reasonable priced but I think the big draw is the unique atmosphere.
It gets busy on weekends and some of the more unique and comfortable chairs/areas get special reservations. Weeknights and you'll probably have your pick without reservations.
It's on the street where the Santika Club fire occurred and some taxi drivers still refuse to drive down that street at night because of ghosts running across the street from the fire. Only in Thailand. Print out the Google map for the taxi driver or go to the web page for a map in Thai. It's in the Ekkamai area of Bangkok.
http://maps.google.co.th/maps/place?hl= ... 2129102184
This review pretty much sums it up for me:
http://www.bangkokrecorder.com/tuba-15