All right, everyone's doing it since the news a few days ago, so here goes:
"No More Heroes" by The Stranglers
Get the album and the video game that takes its namesake, because there is absolutely nothing else like it. Why would it make a good Rock Band 3 song? Complex guitar and keyboards will make it quite the challenge, and they interact nicely.
"Reelin' In The Years" by Steely Dan
Did you play through Steely Dan's "Bodhivasta" and thought "Fuck this noise, I'll never like Steely Dan"? Well, this song's much easier on your poor little fingers. It has interesting parts for everyone: the keyboard plays most of the rhythm with guitar coming in for a little lick every so often. Rock Band needs moar Steely Dan!
"Lily, Rosemary and the Jack Of Hearts" by Bob Dylan
Youtube doens't have any good videos, just covers. Aaaaaaaaaaaanyways, it would be a pretty boring song overall, but the story told is damn interesting, and everyone would be too focused on what's coming out of the vocalist mouth to care that they've been going over the same pattern for eight minutes. Then again, if they did "Tangled Up In Blue"...
"Super Rad" by The Aquabats
It was either this, or "Fashion Zombies", but I figured let the Charge!!! album be DLC, because gosh darn it we need something to balance out the depressing indie. Plus, I've been working on my MC Bat Commander voice for a while now, and it's almost as good as my Sean Connery. As far the song itself goes, it has all the hallmarks of ska: busy bass, complex drum beats (courtesy of Blink 182's Travis Barker).
"She Is Beautiful" by Andrew W.K.
Sure, I guess you could have DragonForce if you want metal with pianos in Rock Band 3. You know, if you're stupid. Andrew W.K, the king of partying and the inventor of hard, needs to be in this game, and not just his song, oh no. You know how in my Green Day Rock Band review I said I'm a sucker for the linear mo-cap? Seeing your guy bounce around like AWK would be TITS! It would be ACE! It would be... awesome! The guy's a pretty accomplished pianist, so naturally he plays it in most of his songs.