I generally tend to like whatever the anime/manga has going for it as long as it has my interest, like the fights in Fairy Tail & One Piece, shock value in Akame ga Kill (sucker for that stuff), some fan service as long as its not going overboard, etc etc. Just an easy to please guy in general, but I'd be lying if there were stuff I don't hate.=/ Excessive flashbacks for starters, which puts me off from Naruto ALOT, like an entire manga volume dedicated to Sasuke's childhood & a flashback telling about Sakura's hair during her fight against Ino? Screw that, I generally hate any flashback more than fan service thanks to Naruto, & Pacific Rim had a huge flashback when I saw the movie. Another pet peeve of mine would be CGI, its used in a ton of movies these days & its gotten into anime as well.=/ If done right its fine, however too much of it is just.......yeah. I can't name alot of anime that has bad CGI other than the new Sailor Moon anime, but for movies, its now "pay this much money to watch our CGI", last movie I saw was Godzilla, but that was because I grew up with Godzilla.
Didn't mean to go for a little rant there.@_@ I just really, REALLY hate pointless flashbacks.