wow.. great question. well, uhm, you say a good winning team here's what comes to mind:
lakers - they have huge fan base, really, and KOBE is there. nuff said
cleveland - ohio fans are not really that much of a bball fan, so here's a good team with less amount of fan base. plus if you like LeBron, this is your team
celtics - they just won the chip, they have the "big three".
mavs/suns - they're prolly the most consistent good teams in the league
bulls/miami heat - they are rebuilding right now. adding young talents in their respective rosters..
den nuggets - if you like great offense, this is your team.
bucks - andrew bogut's team. there's a saying, love your own, right?
gs warriors - like the nuggets, they're a great offensive team, plus they've got the laudest crowds in the L.
new orleans hornets - they've got the best point guard in the league right now.