I don't really know about the quality of hotel in bangkok but I think it will be better if you choose somewhere around MRT or BTS station because it will be hard if you must to take a bus. maybe you can use a van but almost all of van is on victory monument (maybe you can choose somewhere around there).
BTS and MRT Maps
I think it will be better if you stay around siam, chatunchak, sukhumvit and silom.
If you stay near siam you can take BTS from Ratchathewi, Siam (CEN), and National Stadium
if you stay near chatunchak you can take direct bus to Victory Monument.
Everything will be easier if you stay near BTS or MRT station because you can just walk to the station directly.
I'll give you some advice to choose your place to stay :
#1 Low Budget :
you can find your low budget place in "Hostel World" (Link to Hostel World)
it's really famous among backpacker.
#2 Family Trip :
if you go with your family you can find more ex and more comfortable place to stay, you can check that in Agoda website or tripadvisor website.
#3 5/4 stars HOTEL :
for the best place and has a really unforgettable you can check on bangkok.com and I think if you stay around siam to on nut it's quite ex and really glamour especially thong lo. when I go to thong lo it's really nice place to hang out :D and you must to pay more.
okayyy :) see yaaaaa ~
Warm Regards,
Fita Paulin