With the new airport express in action, downtown is only 100bht($2.50) and 15min away!
Good places on the Sukhumvit Road where there are plently of restaurants, bars and market stalls around are Ambassador Hotel (40USD a night, 3.5*) or Le Fenix by Accor Group (same price, but small boutique place - its where I normally stay)
There is no shortage of hotels and price ranges in BKK. Its probably the best city in the world for hotel options!