The list is pretty.....pretty.....pretty....pretty.....pretty long.
Depending on the threshold you want to use, here is the list:
New Jersey Nets
New Orleans Hornets
Los Angeles Clippers
Sacramento Kings - (only won as the Rochester Royals)
Oklahoma City Thunder - (only won as the Seattle Supersonics)
Atlanta Hawks - (have not won since move to Atlanta)
Washington Wizards - (have only won as the "Bullets")
So that's 13 - 17 teams with no championship.
And the Dallas Mavericks just came off this list this year.
Utah and Phx are the only 2 teams on that list (maybe indy) that surprise me. They are teams that are historically good. The rest of the teams have had some upswings but, really, are not what I'd call superior frnahcises.
+ you gotta take Washington off that list. Same team. Same city. Its just a different name.
If you look further into it, it's more about which teams were lucky enough to have the stars that were capable of winning. Lakers were lucky to have Magic/Kareem and Shaq/Kobe. Bulls were lucky to have Jordan. Spurs were lucky to have Duncan. All those players could have won in any city, just the ping pong ball landed the right way for them.