Just so you all know, Clarissa was an awful show. It was boring and even the horrible laugh track didn't seem interested, like a parent patronizing their kid as they read the newspaper.
The point Nickolodeon went down the shitter was when they fired Spumco and made their own Ren and Stimpy. Spongebob is an awful attempt to do R&S over again completely under their control, aka in a generic Nick way. Yes, this 'attempt' is working quite well, but Spongebob didn't almost single-handedly change American animation from a stagnant cesspool of toy commercials and uptight garbage to what it is now (lewd garbage).
Are You Afraid of the Dark? Not after seeing this show. If that's what's in the dark, then whew! We've got nothing to be afraid of. The show was less scary than Rugrats, which was an okay show. It was the best in the beginning until Nick realized they could drag it into a franchise and made movies, where it became rather crap. Doug was a horrible waste of animation cels. Rocko is the best Nicktoon in a post-Ren and Stimpy world, and Aaah! Real Monsters was okay, but that's it. The rest is inane nonsense. I'll admit I only saw one episode of Invader Zim, the first one, but it just didn't look interesting at all. It looked generic humor-wise.
Pete and Pete and Salute Your Shorts were the best of Nickolodeon's live action stuff, but Salute Your Shorts was more like a "good because you were just a kid" type of good. And the rest of Nick's shows are pretty rotten. I actually rarely ever gave Hey Dude the time of day, though, so I don't know about that one. It just looked so dumb.
Everything on current Nick is like the last few seasons of All That. Not all that. Actually quite awful and generic. I can't believe they have a sitcom where the kids are part of a rock band. Have we not progressed as a society beyond The Partridge Family? *Nickolodeon execs shake their heads no and produce a second rock band sitcom*