The touchpad is a good example here. I've got an HP with a large touchpad, and with the buttons implemented in software. It's horrendous to use in a situation where I'm mixing left and right clicks, while expecting the cursor to stay in one place (games, file management in the GUI).

I don't use Macs often, but that's definitely one place where Apple is so far ahead in their implementation that it's not even funny. Using the touchpad for anything more complex than surfing the web is much more comfortable.