I like: a logical plot with build-up and tension, character development
I hate: deux ex machinas, telling instead of showing, cliches, characters who are overly-emotional to the point of stupidity
premise aside, when the main character always wins some way or another (eg. Izuku from Hero Academia, MC from Quanzhi Fashi)
I rate things on a relative scale based on a mix of how much I enjoyed the anime as well as how good the story actually is. In general, I don't enjoy slice-of-life animes as much as other genres. So even if the story is good, due to my bias, I usually rate it lower (eg. 5 cm per second)
If something is rated lower than 2, it's either because it is/has
1. no plot, no tension or build-up, OR mind-numbingly slow-paced, so boring
2. an anime about an MC who is a social outcast and then somehow becomes OP and gets power, women/men, fame/money. In addition, these things are usually gained without any struggle. This type of anime is usually targeted to people who want to live vicariously through the MC.
3. meets one of the two from above, but has no redeeming feature such as comedy or a likeable protagonist