EARLY childhood (pre-pre-teens):
Looney Tunes
Pink Panther
Scooby Doo (pre-Scrappy)
Voltron
Transformers
The Littles - I recently introduced my youngins to this one... Wow, I forgot how much influence ABC had over their content, back then. Twenty-three minute morality plays, each and every one.
Batman - Yes, the live-action show, but who are we kidding?
Mid/Late childhood:
Animaniacs - Have the 5-disk set (Volume 1?) and they're as funny as they ever were. I almost feel bad that my kids may never get 2/3 of the jokes.
Batman: The Animated Series - Started getting these in the mail via Netflix for my daughter who loves The Batman (which stands head and shoulders above "The Brave and the Bold"). I'll admit, the art is more stylized, but also more refined, in the newer series... but the old ones still have a special place in my heart.*
Duck Tales - This was a (mildly) guilty pleasure of those years... and would never have admitted watching this in school.
X-Men - I was hooked from the first episode when Gambit answered a passerby's question of "How did you do that?" in his casual, N'awlins way: "With style." (And, as much as I personally love the character, Wolverine wasn't the bloody center of attention. Yes, I'm looking at you, Ratner.)
*Except for the stupid "Christmas" episode with Robin showing up out of nowhere, to (thankfully) not be seen again for a season or two later.
Basically, the weekday afternoon line-up...
Wish I'd seen more of:
Exo-Squad - I frakkin' LOVED this show. A coherent storyline across a long seasonal arc, in a 30min cartoon? Bloody unheard of... Looking back, I get a serious BS:G vibe off of that show.
[insert popular mecha animes of the last two or three decades here] - I caught snippets of Robotech, and later a few "Gundam" shows, but never enough to really get drawn in. Part of it was that I only got ABC and WPBH (PBS) where I grew up... and CBS, but only on weekends when I was up at my dad's. And later, I just couldn't get away with the broadcast times (late night, generally).