I have:

 ACTION FIGURES.

T-Shirts that read; "Choose your weapon" with several sided die depicted.

                            "Head Nerd" (Gift from my wife when I ran the game store)

                            " Schrodinger's cat is dead" (front) Schrodinger's cat is NOT dead (back)

I play 40K, Warhammer FB, Malifaux, and several other games that has people shaking their heads.