AppleCare is pretty damn good if ya ask me. Hell, my Mighty Mouse and keyboard have each been swapped twice in the 3 years my iMac has existed. That **** paid for itself. (169 for the AppleCare - 200 value in apple stuff. Not to mention if I ever need a new shiny display or something.)
Besides accessories with the computer though, Desktop applecare gives you onsite repair too. (IE: someone coming to your house) though that only rings true for iMac and Mac Pros. And they have to live within a certain mileage.
I'll ring the "please get it for a laptop" bell one more time. Anything you're mobile with is almost a must. I had a Sony Vaio hard drive crap out on me after a week of carrying it around. (It was fixed, btw. I'm a huge fan of that computer.) But the point is computers are fragile - most especially the ones you can carry under your arm.
Two tricks I've learned with AppleCare -
eBay has it really cheap. I know this has been brought up before, but my experience was pretty awesome. Aluminum macbook is still under warranty according to Apple's support site.
Or, if you feel more comfortable with the legit route - walk into an apple store with a student/teacher, or an old student ID. Guaranteed at least 50 bucks off the AppleCare with the discount.
tl;dr? short answer: get it. you'll thank yourself should something unforeseen happen to your Mac. It is a machine after all... not a god.
Please, don't buy AppleCare from eBay. It's too risky to be viable. Lots of scams out there.