When ever I get to the part of the scene where I am getting into overlap and follow thru, it gets me excited. It means that I am almost done with the shot and I am adding the last details. These details are so important to make it look correct. In the case of animating the antenna on a character, as in A Bugs Life, the antenna really helped keep the character alive. The were not just floppy, they had to be animated to reflect the attitude of what the character was feeling. I also enjoy doing small details on characters when they hit a pose quickly. Jiggle Settles for instance. Doug Sweetland, a Toy Story veteran, was well known for having these intricate jiggle settles on his characters. It added a sense of hyper realism. It also became a stylistic choice. As you animate for years, you start to develop things that set your work from others. So when you have to animate those floppy ears, or jiggle the fatty parts of your characters, do it right, and do it with style. As the industry turns Hi-Def, all these small details are going to be easier to see. Our life as animators is getting tougher because of how high rez everything is, and how stylistic the characters are. One thing to always note is where you eye will be directed. As animators, we look at our shot over and over, but most viewers see it only a handful of times. Its important to get the overlapp right, but more important to spend your time in the areas that count.
Some well done stylistic overlapp that I can remember off the top of my head is:
The Penguin in the Wrong Trousers (the red rubber glove on his head)
Madagascar had some amazing tail animation on the lemurs king
Jungle Book (any of Milts work on King Louie)
Woody coming out of the box in TS2
I'd love to get people to site some other great examples
There are so many. Sometimes I choose to let the computer figure out certain aspects of the overlapp. Its hard to go in and exaggerate when you are burnt out, but it can make all the difference.
I forgot who said it, but great overlapp can turn a mediocre scene into a mediocre scene with great overlapp.