I have several posts about this on my blog--but here is my list so far:
Poor grammar in online profiles, and in general
Must know something about my career field
Fake bull testicles hanging from the tow of your truck
Crude bumper stickers (like "Orgasm Donor" and "F**K the Haters" in large size across the back window of your truck)
And I think I may add anyone who wears an Hawiian shirt more than once a year (if you're not from Hawaii)
Fun thread!