I do collect Bandshirts. I have one from nearly every band / artist I went to see live (some times multiple) and some more. I stopped counting when I reached 100 shirts...have gotten several since that. On the downside my closet is overflowing....on the plus side I rarely have to wash shirts! xD
I also collect concert memorabilia. I have every ticket I ever had on my wall with things like setlists, drumsticks and picks pinned on there too. Everything I managed to snatch (nothing bought). Everything autographed where I was able to get one. The ones I charish most are my two Mike Portnoy drumsticks (one with Adrenaline Mob one with Flying Colors), my Vinnie Paul stick (ex Pantera) and my Steve Vai setlist.
What other stuff do you have?
Sides a few autographs I got:
Heaven Shall Burn drumstick and pic, half a Machine Head drumstick, a battered and beaten Killswitch Engage setlist socked with the sweat of Adam D., Billy Sheehans Mr. Big setlist, Sepultura setlist and a pick from Adreas Kisser, Adrenaline Mob and Flying Colors setlist, a piece of Mike Portnoys stick from Transatlantic and a Wilco setlist.
Also pics from Therapy?, Black Label Society and Steven Wilson (one from Blackfield, one from the solo tour).
And a one of a kind drawing of a beardfish by Rob from Beardfish.
Another special one to me is the broken stick from Emil of the Broadway Killers (follow up band to the Pinboys) which I took home from the first gig I organised and mixed solo.
All aquired within 3 years.
It is not that much yet, but I am getting a lot better at getting stuff (or I just have a lucky streak).