Well, since the pop sensation refuses to die down, I think that The New Kids On The Block should've stayed together. I still think they are better than N'sync and the BSBoys. Jordan was my favorite. Yeah, I went there.
Other than that,
Brownstone
TLC
Dawn should not have left Lucy Pearl (could someone PLEASE tell me what happened?)
The Fugees
Digable Planets (Where are they now? Are they disbanded?)