I actually still really enjoy the old full-length cartoons, too
Before they had 'the formula' nailed down so tight, there was some genuinely weird stuff. Like the "Pink Elephants" song in Dumbo (which was a representation of his accidentally drunken state), or most of Alice in Wonderland. Can't imagine anything like that making it past Disney Board of Artistic Decision Making and Market Positioning (or whoever decides what goes in their movies today).