I would have to say i don't have one favorite rapper a few i enjoy are styles of beyond, Mike Shinoda, Kanye West ( on some days ), Nas, Venom( outstanding musician everyone should hear his rhymes), Lupe Fiasco, and thats about it. I think too few people have really listened to rap music and only have a small understanding of what it really should be because too many "rappers" are only in it for the money and put little thought into there lyrics.
If you feel rap is a waste of time listen to "Dumb it Down" by Lupe Fiasco you may find yourself in a different mind about rap in general, if not, well you have a right to your own opinions but before you judge just give it a chance
http://www.youtube.com/watch?v=q1Et1siZhTk