For those looking for more arcade fun in their hoops action, NBA2K offers up 'arcade-style' no-rules mode, but that's really a waste of a fine simulation. Go with NBA ShowTime instead.
For hoops fans who like their b-ball games to mirror reality and are looking for a reason to own the Dreamcast, NBA2K is the killer app they've been waiting for. Those who already own the Dreamcast should consider themselves lucky because not only is NBA2K one of the first B-ball games out of the gate this season, but it's also clearly the best one. There's no question why you shouldn't own it, but keep in mind that you'll need to either clear your VMU or buy a new one because NBA2K will fill one up entirely on its own.
For all other system owners, tough luck. NBA2K is a Dreamcast exclusive, so either pony-up the dough or get off the bus. NBA Live 2000 for the PC is the only competitor that comes even remotely close. All others look like welfare cases compared to the wealth of NBA2K.