I used to make it my mission to buy old videocassettes of cartoon shows I'd watched from the 80s/90s and am trying to get DVDs now, but it's a little more expensive since they keep coming out in complete season/series box sets. Thank goodness for the internet... OK, shows I remember liking:

Transformers
Beast Wars/Machines
He-Man & The Masters Of The Universe (modern one's better)
She-Ra
The New Adventures Of He-Man
Teenage Mutant Ninja Turtles (the modern one's cool too)
Thundercats
MASK
Visionaries
Dungeons & Dragons
Ulysses 31
Batman (TAS, Adventures of Batman & Robin, New Adventures)
Superman
Batman Beyond
Justice League
Spider-Man & His Amazing Friends
Spider-Woman
X-Men
Spider-Man (90s)
Incredible Hulk (70s/80s and 90s)
Marvel Action Hour
Silver Surfer
Bucky O'Hare
Where On Earth Is Carmen Sandiego?
Captain N: The Game Master
Pole Position
Battle Of The Planets
Defenders Of The Earth
Phantom 2040
Jayce And The Wheeled Warriors
ExoSquad
ReBoot
Gargoyles
The Legend Of Prince Valiant
Pirates of Dark Water
Droids
Ewoks
Captain Planet
COPS
Centurions
Adventures Of The Galaxy Rangers

Probably more I can't think of right now.

Oh, and I watched the Highlander cartoon although it SUCKED.