Im sure few would agree with me on this but
the original "
Heavy Metal" movie is the first to come to mind
no, the animation isnt fantastic. no, not for the nekkid women aspects. yes, the stories were pretty mundane by current standards, but still. it was (as I recall) all hand drawn and animated, was pretty 'cutting edge' for the time and is more than a little into the realm of 'cult classic' than anything else.
since I saw it wayy back during its original screening, its just always been one of my faves. worked long and hard to snag a bootleg of that a few (ok, more than a few) years ago.
<shrug>
edit: oh yeah, and I still have the soundtrack I listen to quite a bit...
