I'm a liberal I would say, if you were to categorize my beliefs (at least in a social sense), but one thing that really irritates me about liberals in general is their blind prejudice towards making generalizations.
Sometimes, generalizations are useful, or so often correct that they are perfectly reasonable. For example, it's a fair generalization to make the sweeping claim that members of the Ku Klux Klan are racist. Sure they might be a couple members who just wanted to fit in, or wear funny hats and capes, but actually have nothing against black people, but on the whole, nearly all members of the KKK are racist, because it is a racist organization.
What really annoys me though is that some people are so against generalization that they will tell white lies in order to avoid generalization, or they will commit 'fuzzy math'. For example, if I said 'Nevada is so ugly, most of it is just barren desert' they would say 'no it's not, it has forests too, don't generalize'. Of course Nevada has a little bit of forest, but at least 90% of the state IS barren desert, but in order to not offend people who get butthurt about statements of majority, I would have to pretend NOT most, ie less than 50% of Nevada is desert to make people happy. Even though it is not true.
I guess what annoys me most though is people just being anal due to the adjectives I use. If I make a broad statement, more often than not I mean 'most' cases, not every single case. I don't think I should have obliged to clarify with a 'most' or an inaccurate 'sometimes', or even if I should, it's just kind of rude to tear people apart based on minor semantic mistakes.