Ugh.. a lot of you just aren't thinking! Almost all of your suggestions simply would NOT work on RnRc!!
Here are all of your suggestions and why they would not work:
Weezer - Doesn't work because they aren't popular with most adults.
U2 - Might work, but most of their songs aren't "rocking" enough for a roller coaster soundtrack.
Creed - God no. Their music is absolutely terrible. Nobody wants to hear a ballad about having a child with Scott Stapp wailing his Eddie Vedder ripoff voice while riding a roller coaster. Not to mention they are so horribly overplayed that I don't know anyone that isn't completely sick of them.
Red Hot Chili Peppers - They would definately work - they've been around a long time, they're well known and liked by young and old. The only problem is their lyrics are a little dirty, but then again, so are Aerosmith's.
'N Sync - Only teen girls would ride.
Rolling Stones - Maybe, but most kids and teens don't like them.
Madonna - Isn't Rock Music.
The Beatles - Would work, but 2 of them are dead, so it would be impossible that they were giving a concert and wouldn't make sense. Plus they'd have to use 2 fake members and I'm sure nobody would want to see that, especially Paul and Ringo.
AC/DC - Probably one of the most likely choices.
Ozzy Osbourne - He could work as long as he cleaned up his act a little for the pre show. But since he has such a bad reputation of being an alcoholic and drug user (which is now very known thanks to his show - The Osbournes), he is not "Disney" quality.
Linkin Park - Only popular with kids and teens, most adults couldn't stand them. Plus, they won't be popular much longer anyway.
Dave Mathews Band - Sorry, wuss rock just doesn't fit a rock 'n' roll themed ride.
Eminem - uh... no.
KISS - The most overrated band ever and biggest sellouts. They only have ONE well known song anyway.
Incubus - Like a few of the bands mentioned, Incubus is only popular with teens, thus ruling out adults. Like Linkin Park, they won't be popular much longer.
Nickelback - See Incubus.
POD - See Nickelback.
There you have it. Of all those, U2, AC/DC and Red Hot Chili Peppers are the most likely choices.