Depends really on how you define great drafting. Is great drafting finding studs with your top picks like Paxson has done or is it finding good players without having great picks(Buford). Two very different things.
Riley has done well. Haslem, Wade and Wright most notably.
Buford has gotten Parker and Manu without ever having a good pick(not to mention Duncan the year he did). He also drafted Barbosa but traded him right away.
Colangelo has done pretty damn well with Phoenix over the years. Marion, Amare, Nash(even if they didnt have the patience to see it out), Barbosa(through trade) and a few other good ones over the years.
Isiah actually has done very well drafting. Stoudamire, McGrady, Camby, Frye, Ariza, Lee and co. Shame he is so bad at the rest of the team building thing.
Buford has Duncan, Parker and Manu and if Scola and Javtokas ever come over those two should be good also.
Ainge has done well, though his players still need to prove themselves. Green, Jefferson, Perkins, Delonte, Gomes and Allen.
No doubt that Orlando and Toronto have the worst records over the last 10 or so years. Since the Webber/Penny pick Orlando has picked Mike Miller, Corey Maggette(gave up on him before he became anything), Dwight Howard and Jameer Nelson. Everyone else has busted completely. Toronto since the Tmac, Camby, Carter and Stoudamire drafts have managed to get Bosh and Mo Pete. Sow is their next best draft move.