KOkay this is were things might get a little messed up i have always argued with everyone over this topic I say ROCK is better no matter what if you say otherwise or if you agree REPLY.
Most definetly rock, it takes more time to learn how to play a guitar WELL than it takes to learn how to chain rhymes together...Therefor, rockers have much more talent than rappers, thus making rockers amazingly awesome....
Rock in general takes more talent to perform (not create, but an actual on-stage performance) and generally has more intelligent and well thought out songs, though I will say there are always exclusions to the rule. I do enjoy listening to both, but if I had to choose one it would be rock.
I prefer rock over rap. I find that the part of the music i enjoy is the instruments, not really the vocals. A large part of rock is that the band plays their own music. Rap is more of vocal style. One or two, or even a group perform vocally, with (in most cases) beats made prior to using electronic equipment and such. I just find that i connect more with the instruments than the vocals.