Here's some good ones from UCF:
SAE had one that said "Not everyone can be an SAE. Some people have to sit on the curb and clap as we walk by."
ZTA's rush shirt said: "If you're wondering why we're so happy just think about why you're not."
Kappa Sig had this idea but they didn't go through with it because no girl would be willing to wear it.
They have an annual party called "Ship Wreck". The shirt has a picture of a sinking ship and the slogan says, "She's going down and we're all getting off."