For me, I feel dat RnB singers perform best live, but for rap artists, ludacris does a pretty good job.

The Worst are:

50 cent (his club bangin tracks r crazy but live....no comment)

Fabolous (needs to learn that ur hand goes on the handle and no over the speaker part of the microphone, i think he needs tape or sumthin to remind him where to hold)

Nelly (his voice like changes so much)

Check out my soundclick!!! lol
http://www.soundclick.com/twest