This is by no means a comprehensive list, and I tried to stay away from straight-out Saturday morning cartoons...or we'd be here all day.
The Simpsons. More than any other TV show (and a lot of things that are not TV shows), The Simpsons influenced my formative years. FOR THE BETTER. What's kind of sad is that I haven't watched a new episode since at least 2001.
The Wonder Years. Winnie Cooper, I wanted to BE you. This show was a specimen of that peculiar, difficult-to-strike balance between genuine sentiment and silly humor. Genius.
Clarissa Explains it All. I, uh, also wanted to be Clarissa, or I thought I was her, or something.
Are You Afraid of the Dark? Dramatized scary stories, on Nickelodeon. I'm sure I would find it beyond boring now.
Hey Dude. This was the most scandalous thing I watched as a kid, because it involved teens living alone (?) on a dude ranch. Don't worry mom, nothing ever happened.
Square One. So many things I know about math, and retain in my brain to this day, I learned on this show. Don't even get me started on MATHNET, either.
Rescue 911. Hosted by William Shatner!
Zorro. Now that I think about it, every single episode was a lame iteration of the same old plot. But my siblings and I loved it.
Batman. No, not any of the cool Batmans you're thinking of. THAT Batman. The one you see above.
Unsolved Mysteries. If I learned about math from Square One, I learned how to be afraid of the world at large from good old Robert Stack.
Ren & Stimpy. This had to be the stupidest thing on television, EVER. Why was it so watchable??
The Secret World of Alex Mack. This show marks the point where I grew out of, well, shows like this. I liked it. And yet.