Everybody criticizes Isekai, and for good reason. They're formulaic, feature really obnoxious characters, all look the same, and can often be misogynist power fantasies. On the other hand, they're very popular so they must be doing something right. Do you have any isekai that you think are really good, in terms of being fun to watch, artistically worthwhile, and not leaving you feeling gross afterward?
A couple ideas:
Inuyasha - this one's older, from when Isekai stories were usually Shoujo instead of Shonen. It's way too long, but has fun characters and cool monsters.
Tanya the Evil - "The Nietzschean Isekai". I won't spoil it, go watch the first five or so episodes for a wild anime ride. Unfortunately, Tanya the Evil never really progresses any further than the insane premise, so the second half really drags. Also, the art looks terrible and makes me feel terrible in my soul.
Re:Zero - Subaru's story has a lot of the Isekai tropes people hate, not least of all the character of Subaru himself. But, it's full of wild characters and bizarre situations. What I like about the plot is how it makes you think about the different perspectives of the characters as you uncover the reasons for their surprising actions.
Log Horizon is a good one. The story goes from a survival video game isekai to a story about the economic development of a nation and the effects of colonisation. Its still got some familiar anime tropes but the characters are all enjoyable and the story gets pretty interesting.