I've been to a ton of concerts, not as many recently as I would like (the most recent being I think Underoath and A Day To Remember back in October) but I have Primus on the horizon in June as well as the Carolina Rebellion Festival with Stone Sour, Godsmack, Theory of a Deadman, Bullet For My Valentine, Alter Bridge, and more performing in May. As for who I've seen...
* Mudvayne, In Flames, and Flaw was my first concert. In Flames rocked my face off.
* Aerosmith and Cheap Trick was probably the biggest show I've been to.
* I've seen The Bouncing Souls more then any other band, around 4 times I think; twice at Warped Tour, once headlining over Whole Wheat Bread, and once at a show with Rancid and the Independents. I might have seen Through The Eyes of the Dead more times since they were local before they got big but with their constant line-up changes, particularly at singer, it's like a different band every time I see them.
* Cannibal Corpse is the most brutal band live ever. Ever. Psyopus is a close second though.
* I've been to Warped Tour three times; having seen Joan Jett and the Blackhearts, NoFX, Protest The Hero, A Day To Remember, Bad Religion, Underoath, The Devil Wears Prada, Less Than Jake, Pennywise, Anti-Flag, The Casualties, The Pink Spiders, The Bled, HORSE the Band, and a ton other bands a few times over.
* The best pit I have ever been in was either at a Between The Buried And Me show with HORSE the Band where they played the entire Colors album from start to finish or when I saw the Dropkick Murphys with the Tossers and the Horrorpops right after "The Warrior's Code" came out.
* The worst band I've ever seen is Hinder. Fuck Hinder, saw them with the wife at a show headlined by Staind and Three Days Grace. Them or Depswa, a shitty opener for Drowning Pool when I saw them.
Really, I've seen a shit ton of bands.