There's an anime called Shitcom, which is a one minute ONA claymation short where a guy proposes to a girl and then they both vomit poo. That's how you know it's true love.
Granted that feels like cheating so I'll also throw out Rosario + Vampire, Venus Versus Virus, and Hand Shakers. Hand Shakers is upsetting because I watched the show fully aware of how awful it was, and it didn't deliver enough. Like it was bad in a lot of ways, but it's the terrible aesthetic decisions that I watched it for, and only episodes 1 & 6 really leaned heavily into that (not that the other episodes look good mind you). For those who haven't seen it, look at the
stock fire effects poorly layered over the art, I found that stuff hilarious. Like I don't really remember the details about why I hated the series outside of the visuals, but the kind of baffling visual direction of the series was at least interestingly bad. Not to imply it every looks good but you know, it's not always emphasizing it's visual overload.