Best Neighbourhoods in Bangkok?

Bangkok is huge and unorganized urban planning. It have poor traffic all the time. Better to live in neighborhoods where MRT, BTS or airport links lines passed.

For example Sukhumvit area from Thanon Ekkamai to the end of BTS line. There are plenty of apartments and condominiums for rent.   

I prefer to stay near Siam Square - lots of activities around, lots places to eat and very convenient logistics there.

I stayed in Bang Rak and Khao San Road. Bang Rak was more of a business traveler area but lots of swanky hotels. Khao San Road had more back pack travelers like me, but still a nice area and pretty cheap.