A few repeats from the thread
Hate:
-Shows that adapt a manga, light novel, visual novel, etc. and try to cram way too much into way too short of a time. Some trimming is inevitable, but some shows try to adapt things that have such complicated plots that they're rendered near-incomprehensible. The worst case was Occultic;Nine. That show had everything going for it, but its pacing reduced it to a nonsensical stream of noise where you can barely tell what's going on, and not in a good way. Chaos;Head was pretty bad too. Steins;Gate had similar problems but wasn't as bad since it had more episodes to work with.
-Anime that goes on for too long with bullshit. This is why I can't get into most shounen shows, though I do like Dragon Ball even though it's a bad offender in this regard. Hunter X Hunter is another one that I love, but that's because I think even though it's long, it never felt like it was just going on for the sake of it.
-Pointless drama or plotting. See Little Witch Academia: that show was strongest when it was acting like the old Cartoon Network shows it's clearly inspired by and having a bunch of singular, self-contained episodes with no/minimal over-arching plot, but gets bogged down in a drama story near the end. A lot of slice-of-life shows do this too.
-Tsundere characters that are so excessively cruel and bitchy that it's improbable that anyone else would take them seriously and not think they're psychotic. Normal tsundere is fine and in fact desirable.
-Cute girls who turn out to be boys. Then again I think this is supposed to piss me off. Sometimes it has some good humor behind it.
Love:
-Excessive fanservice, nudity, and ecchi content. Unlike most others I think it rarely, if ever, detracts from a series.
-Unique art styles, as long as they still look enough like anime characters to be cute.
-Anime made by otakus for otakus that doesn't even try to make concessions for normalfags.
-Characters that are both unique AND based on classic tropes (tsundere, dandere, yamato nadeshiko, ojou-sama, etc.)
-Almost everything else.