I once saw a guy with a shirt that said 'Cheer Up Emo'. Oh man it cracked me up! Also from Peta you can get shirts with a chicken and the words 'I am not a nugget'.
I gave my dad this T shirt for a present. He's a college Prof. I saw one on the back of a biker's T shirt that said, "If you can read this, my bitch fell off the back of my bike"
"i'm so broke i can't pay attention" then there's a really cool one called "comma sutra" and has all these little comma's in positions.. i'd take a pic but it's my friend's shirt and she lost it such a shame.
"I'm not with stupid anymore!!!" VERY cool way to make fun of those I'm with stupid shirts isnt it? hehe You know from the 6th sense movie .....I see dead people.... a friend has a variation of it .....I SEE DUMP PEOPLE.... And my favoutite " I know jesus loves me but I'm not interested" hehe
The way I used to keep myself from going insane when i worked at Red Rooster was to read peoples t-shirts. One good one was a blonde girl with a shirt saying, "I had a nightmare - I was a brunette."