Weeaboo names: Names that try way too hard to sound Otaku or Japanese like Asaki Saguwatorisaka, Shinjohari Takanishawa, or other names like that should be banned. They don't really break any rules, but they make me cringe incredibly hard. The only time names like these would be acceptable would be if they're from some sort of anime or something (I wouldn't be surprised if the random example names I used are real anime names), but other than that they're trying way too hard.
I'd go through other types of names like how I did above. I'd cover usernames with dumb emoticons in them (like Mooga Mawile :3), edgy usernames, yellow usernames (the color yellow sucks), spammy usernames, and more. Those are just some examples I got off the top of my head, I could come up with more if you need.