On the Internet, everyone is judged by a list of their interests. I also hate people that make large lists of their interests, because no one reads them, and it looks pathetic.
Also, people that don't take the time to spell correctly or use proper punctuation and capitalization. I let the capitalization slide on AIM, but generally, anyone who types like a dumbshit is either ignored or mocked. If you're a poor speller or a slow typer, tough shit: I don't like dumb or slow people either. Errors in grammatical structure and such are fine.