Well, much to the chagrin of my girlfriend, I like obscure and weird T shirts.
A couple of my faves:
My Old “Beaver Sunblock” tshirt: A actual sunblock from Hawaii, it gained noteriety by having shirts with a girl holding up a tube of it and saying “Hey guys, let me rub some of my beaver on your face.” It actually got me a stern warning in high school
My Charlie Brown shirt: Not a pic of Charlie, but a yellow shirt with the black zig zag at the belly. Everytime I wear it, someone points at it and goes “cool shirt!”
and my Etch a Sketch Tech Support shirt:
Wearing this one at any computer convention gets some big laughs. Most tech support ppl would agree