Enh... they're both awesome games, i can't decide, but I do like Guitar Hero On Tour. (I know it's for the DS but come on, it's good to have on hand in case you get bored out of your mind waiting for a bus, or on a plane
Speaking of Rock Band, Guitar Hero: World Tour will have the same set up as Rock Band. So it's great for any hardcore Guitar Hero fans who want the...greatness...of Rock Band, and includes song customization. The Rock Band advocates will probably call it a knock-off of Rock Band...
I have never experienced the so-called "greatness" of Rock Band, so I have to go with Guitar Hero by default...
Rockband defenitly has more to offer (guitar, bass, drums and vocals) and the ability to creat your own character so in my books Rockband gets the trophy in this competition.