I think I posted a topic about this a few months ago, but doesn't hurt to have a chat again.
What are some terrible fanfics you've encountered? As you can see, I've read Starkit's Prophecy, but I've also witnessed the glory of My Immortal and... "supper smash bros Mishnoh from God." Don't know if I spelled that correctly, but you get the point.
In general, bad fanfics are a guilty pleasure for me, save for some more... disturbing ones. Also, not technically a fanfic, but AO3 tags are a wild ride without even reading the actual stories.
A couple buddies of mine posted outer-space prep school fanfics back in Miiverse's heyday. They were okay at best, but it was middle school-level scriptwriting and they had to abide by the community guidelines.
I have made some bad fanfics. They had bad grammar and a bunch of stuff. I even made some really bad vocaloid characters when I was young. I hate to read the stories. Fortinetly, I write a lot better even though spelling fortunately is still a pain for me.
If you saw the anon chat fanfics before they got vaped...
Anon chat also had some art among fanfics.
Infamous Shrek x Hitler is great.