The beauty of AppleCare is actually not in the replacement and repairs. That's certainly a nice feature, and very welcomed should something happen to your machine. I'd recommend it highly for laptops, as it's just the nature of notebooks that they are quirky, the parts are smaller and run hotter, and generally they have shorter lifespans. Apple makes very high quality products, but it's still a notebook, and you're still rolling the dice a bit.
That said, the REAL beauty of AppleCare is that at any time you can call Apple tech support and have them walk you through virtually ANY problem, issue, or question that relates to your Apple product. They technically don't support third-party stuff, but if you get a nice enough agent sometimes they'll help you out there as well.
I personally don't use this feature much since the vast majority of the issues I run into I can fix myself, but for people who aren't comfortable working inside their computer or who really don't know much about the technical workings of the machine, AppleCare is well worth the money.