I like pop music, but I hate the fact that these days 99% of it is crap and over-produced (Britney, Christina etc). People also do not realise that there actually are pop artists that do good pop music and express themselves that way. That might be due to the fact that these artists are not very well-known though. I hate the generalization of pop music = crap.
I like classic rock music, but I hate it that I am therefore supposed to know every band's whole discography, released singles, ex-base players and tour dates from the 70s by heart.