Frankly, I'm surprised that the only one JKR chose to out was Dumbledore. For my nomiation, we have Lockhart, Sirius, and Remus in the So-Obvious-It-Hurts category (Remus, well, half-and-half).

Hooch for the 'It's a stereotype and I'm going for stereotypes" category.

Trelawny for the "Too ditzy to notice there IS a difference" category.

Colin Creevy, for the "Paparazzi? Yeah, right! *sarcastic snort*" category

And last but not least, a nomination for Neville Longbottom for the "Wow, HE'S straight? I could have sworn...." category.