I'm going to recommend
Tron (1982). Yeah,
Tron...
This film has an awesome plot, a wonderful setting, and computer animation unmatched for the time it came out.
If you haven't seen this film and you like computers and/or video games, you should watch it immediately.
This is probably my most favorite Disney movie. As a bonus, aside from the live action sequences and
the computer animation, all the stuff that happens in the computer world are all hand painted cells,
so technically this film is more animation than it is live action.
The soundtrack is primarily done by renowned electronic composer Wendy Carlos (she did all the electronic music stuff on
A Clockwork Orange among other awesome things).
When this film came out, the Academy said that it couldn't receive a nomination for special effects
because using computers was cheating