Rock Band also has an AC/DC track pack. There is no Guitar Hero 70s.
The other Guitar Hero games are:
Guitar Hero: On Tour Decades
Guitar Hero: Aerosmith
Guitar Hero: Metallica
Also, there is no way for me to determine whichever one is the best. It goes in the order from favorite to least favorite:
1. Guitar Hero 3
2. Guitar Hero Metallica
3. Rock Band 2
4. Guitar Hero 2
5. Guitar Hero World Tour
6. Everything else
Rock Band 1 sucked, because it's timing system with hammer ons was horrible and insanely strict. But Rock Band 2 did a much better job.
Also:
Rock Band because it has a better song pick and songs from better artists
It's got more, but not necessarily better. Sorry, but Naked Brothers Band isn't really that good in my opinion.