I blame this show for my macabre sense of humor.
I know children who were scared to death of the show, while I sat their laughing my ass off. And the darker and more psychotic it got, the funnier it was to me.
I think the appeal was that it was just amazing a children's show got away with all of this. Even today, I'm still amazed that Nick allowed them to do half the stuff they did.
My favorite episodes:
1) Stimpy's Fan Club = Ren's total break down is one of the funniest goddamn things I have ever seen in a cartoon. His Macbeth like soliloquy while Stimpy is asleep is the stuff of legend and probably the show at its most hilariously dark. Also...the ending is actually kind of sweet.
2) Space Madness = First episode I saw, and the moment where Ren completely lost it still sticks out to me (that's going to be a common theme in my favorite episodes)]
3) Sven Hoek = Ren has to deal with two blithering idiots instead of one, and his enraged monologue at the end is, once again, the stuff I lived for in this show. Also "Don't Whiz on the Electric Fence!"
4) In the Army = Once again, Ren gets tortured and loses his damn mind, and its hilarious. Also, the Drill Sgt. character is a hoot.
5) Stimpy's Invention = The mark of just how insane this show was. They made Stimpy...fucking Stimpy, probably the biggest dumbass lumox in the history of animation a mad scientist with a laboratory. Ren gets fitted with the "Happy Helmet' so he'll always be happy, and watching Ren struggle to resist the helmet and ultimately succeed is probably Ren's greatest victory in the whole show.