I haven't really saw a good rap show yet, most rappers I saw were in tiny clubs at the time and they just stood there on the tiny stage terribly rapping.
Best rap show I saw was when Xzibit opened up for Mudvayne and Linkin Park in 2003 lol dude actually put on a great set. When I bought the tickets I was like "why in the hell is Xzibit on this show".