For some reason I've stated rooting about on the Tube for old treasures from my childhood. It's not really Japanese oriented but just more a random pastiche of the founding pillars of my childhood viewing (or at least the most memorable intro tunes). 80/90's cartoons were just the bomb and the quality of animation in alot of them actually surprises me even now. Man it also reminded me of the amount of childhood crushes I had on various characters

http://www.youtube.com/watch?v=29l0xAAJT8Y
It's a no brainer but none the less a masterclass in animation intros from Thundercats, I can't think of an intro that can top this in terms of the proportion of excitment offered/delivered.
http://www.youtube.com/watch?v=7yeA7a0uS3A
http://www.youtube.com/watch?v=wR65P73X ... re=channel
http://www.youtube.com/watch?v=UaMo4k7iG7s
Theses two should of course go together (And might as well have been called Body Builder and Super Model). I love the way He Man punches the screen! The last one is their not so good and short lived successor.
http://www.youtube.com/watch?v=-B7zfNG1shE
http://www.youtube.com/watch?v=2e5q6ubDlZE&NR=1
Two offerings from Disney, they had the most amazing theme tunes Tailspin particually. From this we can learn that Chipmonks pull of drag better then bears, take from that what you will...
http://www.youtube.com/watch?v=tnCpMHKCasU
http://www.youtube.com/watch?v=X9dkqXq8-AE
Two British specimins from Cosgrove Hall, they did awesome cartoons back in the day.
http://www.youtube.com/watch?v=OZ4c1X5ene8
This is one of my personnal faves the French/Japanese collaboration that resulted in Ulesses 31. It used to kind of freak me out as a kid, mainly because it dealt with quite uncanny myths woven together from a medley of Greek themes.
A minor disclaimer, I have before anyone says anything only watched the intro's.
So there you have it my childhood cartoon viewing condensed. I know there are tons of ommissions, but there were just too many

