I very much dislike big cities, but sometimes it just has to be done, so on the rather ubnfavourable occasions where I have to stay in Bangkok, I always stay at the Sawasdee KhaoSan Inn. Great location, next to the khao san road but not right on it so you do get some peace from the tourist trap, basic amenities but has A/C, Large Fridge, Minibar, Comp. water, TV with foreign channels, cupboard, soap & shampoo etc. everything you need for just a few nights stay in the crazy city. Also there's no time-wasting with reception, always quick and you can get help with bags if you ask (sadly not always freely offered) they have a small restaurant, pool table, wifi (which sadly is not free but not overly expensive and has a strong connection) + 24 hour security! All in all not a flashy place but in a good spot and has everything you need!