I have been playing Guitar Hero III on my pc the last 3 days, and must admit that I love it :) I did not play its predecessors, but love this third installment. The reason I am writing about it here (and quit playing it for a while) is to show off my first 100% perfectly played song (395 concurrent notes without missing a single one!)... on easy. The song was Sunshine of your Love by Cream (1986).
I finished the career on easy modus, but wasn't able to finish Raining Blood by Slayer (1986), it's just too much for me :) I don't think I'll be ready for medium any time soon, 3 notes are more then enough for me for a while. Since medium and above are too tough for me, I decided to give the easy song's another go. To my surprise, it went a lot better then the first time around and even managed to score a perfect score.
I just played some more and managed to get 5 stars for all first 6 stages.
I also found out that Ruby by The Kaiser Chiefs is available as a bonus song and can be bought (with in-game cash) for $500.
The last thing I am going to add is that I was well on my way towards a prefect score in Metallica's One, but once I made a critical mistake after 376 perfectly played notes, all hell broke loose and I almost ruined it in the end...