Portland I personally love the city, and you're the only sport in town no competition and the fans there are pretty crazy face it in houston the rockets take a far back seat to the texans and astros
Gee, I'm totally different then the other suggestions here. Don't particularly like LA(too big, LAX is a nightmare and people are kind of vapid) or NY(too cramped, people are proudly assholes). Purely based on the city, I would like to play in Golden State, Chicago, or Portland. Those are fun cities to me Philly or Washington would be decent east coast cities as well and Atlanta is also nice. I used to hate San Antonio but as I get older I find it's not that bad of a city and it still has a bit of that old school heart and soul to it.
...also have to say - I'm not a fan of Houston as a city...and I was born and raised there. It has it's nice parts but in general I rate it low on the cool city list. Glad I picked up and moved to Austin....just wish we had an NBA team here(would never happen).