If you're going to get a new NBA jersey, you could think about whichever player is your favourite and get their name and number printed on the back.
Of course, the alternative is to stick with a more popular player, one who scores a lot of points or assists in every game. But I personally think you should show your support for whoever you like watching most.
Some people will want to get an NBA jersey to show their love for past players, like Michael Jordan's record-breaking performances at the Chicago Bulls, or Kareem Abdul-Jabbar's time spent at the Milwaukee Bucks or the impressive fourteen seasons he played for the LA Lakers, winning 5 Championships.
Others prefer to focus on present players, like Kobe Bryant, who's spent his entire career as one of the Lakers, or LeBron James, who started out as one of the Cleveland Cavaliers, before moving to Miami Heat, and recently back to Cleveland.
I'm a big Lakers fan myself, and have always loved Kobe Bryant. But I also think LeBron James is an outstanding player, so would be torn between the two. Whoever you love watching most would be the player I'd recommend you get a jersey for. In case you need any inspiration, here's a great run-down of some of the best plays LeBron's ever made: