What is annoying: Roadies who can't accelerate. Roadie is at a red light. He can't do a track stand so he is inching forward hoping the light turns green before he goes critical. Maybe he gave up and unclipped. Light turns green and with agonizing slowness he rolls forward, apparently still in top gear. If he actually unclipped it will take him (or her, both genders are equally guilty) the next five minutes to get his shoe clicked in because he does it in the super slo-mo generally reserved for football replays.
What is yucky: Chunky roadies who wear blue spandex that has big sweaty blocks all over it and they won't let you go by even though they can't seem to get past the 17mph mark. I'm looking at you middle-aged guy on the white Cervelo whose shorts were so tight I was reminded of a balloon with a string around the middle.
What is so disgusting I almost lost my lunch: Bicyclists who cover one nostril with one finger and blow snot out the other side. I can't believe I have to say this people. USE A FUCKING HANKY.