Rock N' Roller Coaster is by far not only my favorite WDW ride, but my favorite ride ever!
Usually I get a little antsy waiting in line, but I don't even care about the wait for RnRC because the whole time they play Aerosmith music! And being that Aerosmith is one of my favorite bands ever (right up there with Led Zep, the Stones, the Doors, and the new band Velvet Revolver - think old Guns N' Roses minus Axl and Stone Temple Pilots front man Scott Weiland) I actually enjoy waiting in line for a half hour or so.
The pre-show is like 100 times better than the one for Test Track. And I love looking at the posters for bands back in the day, my favorite is the one of the Doors I think. Then when you're in the "alley" waiting for your limo to show up you get to see the other trains taking off into a big black hole - it's amazing.
My favorite part is having Steven Tyler screaming the countdown in your ears and you know that you're just gonna go! I don't even realize the first two inversions, just the ending of the second one depending on where I'm sitting, which usually is the front seat. The rest is just a series of turns and one more inversion that you can feel a little more than the first two, but it's not a loop, it's a corkscrew I believe.
The only bad part is, like some others have said, is that it's too short. I usually get a FP, wait in line, then swing around and go on again. Well, that's what I did in summer, anyway. A few weeks ago I just waited the 10-15 minutes so I could hear the good songs!
Oh, this was also the first big roller coaster my sister, who was scared of everything, went on! She loved it so much that we went on it four times in a row!