I actually much prefer a lot of the early 2000's work than I do the "classics". Films like Emperor's New Groove, Lilo and Stich and The Incredibles. Despite growing up with the older ones, they don't stick in my memory as much.
If I had to give a shout out to any old films, it would probably be The Lion King as others have mentioned, but more importantly The Jungle Book which still has one of the best Disney villains to date in my opinion. A great story with a great progression (which admittedly wasn't all of Disney's doing) and sheer genius in the choices of voice actors. I just find it astounding that Mowgli is still alive and had been working in films until 2006.