1. Angel Beats
2. Redline
3. Space dandy
4. Kill la kill
5. nichijou/my ordinary life
I went to Anime North recently and like 40% of artwork and costumes were League of Legends, 10% was StevenUniverse/AdventureTime/GravityFalls, and 1% Kill la kill, so if you want to sell a ton you can make art of all of those things. If you don't think you're as good as the other artists there then you should definitely aim for niche content. I dislike buying prints or buttons but they're probably what sell the best since others like them and they're easy to display and manufacture. I prefer art books even if it's something I'm not super interested in because art books have a ton of art and they're easy to store. None of the artists there had art books :(
Ciullo-Corporation
I would gladly help you but I don't either like anime or follow any AA alley, sorry.
Best of luck anyway!