Lemme get a checklist going:
Batman: TAS - As Jimmy said, it seriously held up. I watched Mask of the Phantasm again recently and it's better than Batman Begins and I liked Begins.
X-Men - Still fun, but doesn't hold up nearly as well.
Spider-Man - Utter garbage in retrospect.
Gargoyles - Hold up almost as well as Batman.
Exo-Squad - I'm still waiting for a DVD of this. I have no idea how well it holds up.
The Simpsons - Going back and watching episodes from when I was a kid, they're even funnier now that I'm old enough to get everything.
Darkwing Duck - When not taken seriously, this is still surprisingly amusing as a satire.
Boy Meets World - It goes half and half. I can accept the fact it's aimed mostly at children, but there's enough for adults in there that I could picture myself watching it with my kids someday.
Whole tons of Disney Stuff - When I was in my teens, I shit all over this stuff, but as an adult I can see that a lot of this stuff was actually really good. I long for the days when you could actually show violence and death in a kids' movie and portray it as something real that we all have to deal with yet not go overboard.
Indiana Jones - The first and third, yes. I really cannot rationalize Temple of Doom as being a good movie, though.
Star Wars - Fuck yes!
Salute Your Shorts - Always gonna rule.
I've been meaning to check out the Super Mario Bros. Super Show DVD set to see if that holds up. I fucking loved that show. I've seen a couple episodes of the Legend of Zelda and realized it was garbage, so my hopes are not high.
Then there's a long list of utter garbage that doesn't hold up and should be lumped together - Power Rangers, Family Matters and Step By Step.
Contrast this with now, where all I watch regularly on TV are Heroes and Lost. I watched a lot more TV as a kid.