I think I posted the parade scene already, but here's another great one from Ferris Bueller:
http://www.youtube.com/watch?v=FqV1TB46lw4

We actually studied in school about the painting that Cameron stares at - "A Sunday Afternoon on the Island of La Grande Jatte." Another that we studied, "The Bath," is also in this clip. Almost makes it interesting to learn about, when it's featured in one of my favorite movies. ;\)

The Jerk
http://www.youtube.com/watch?v=rxhMCkcOwZk
This was on TV a few days ago, and my brother caught part of it. He loved this scene, which is really saying something about this movie, because he doesn't laugh at much unless he "discovers" it himself.

And some Blues Brothers for DA...

Rubber Biscuit
http://www.youtube.com/watch?v=jYyBZE0kBtE
I'd try so hard to imitate Elwood on this when I was younger.

I Can't Turn You Loose and Hey bartender
http://www.youtube.com/watch?v=FyToSF2ngfM

Jailhouse Rock
http://www.youtube.com/watch?v=DebG06_CPmc

They had great chemistry. You can just tell they are all loving what they're doing.