Anything MCR :'( never got to go to one because I became a fan after the breakup.
Woodstock. Hippie fest, man. XP
Fall Out Boy: Any one of them
My Chemical Romance: ANY, I mean any. Just to see them
Soundwave: this year. I know it may not be considered as a concert but Green Day, Panic! At The Disco and A.F.I were there
Fall Out Boy's tour which came to Australia last year but I didn't get to see it :"(
A My Chemical Romance concert,easily.
For an actual "past" concert I would have gone to a Nirvana concert. :3
For a more "recent" band, I would have liked to go see another Skillet concert.
Probably the Beatles.
One with the band Peter,Paul and Mary or The Beatles
Guns n roses the Beatles... Um... Ooh! QUEEEEENNNNNN!!!!! And (even though they're still doing concerts lol) Bon jovi! Maybe kiss. Van halen and journey. Yep.. That's just a few lol
The Smiths, anywhere.