I have never purchased extended warranties on any of my electronics, except for one time when I bought a Toshiba laptop. The warranty covered accidental screen damage, so if you dropped it or closed it on a pen and cracked the screen, it was covered. I paid an arm and a leg for that warranty, feeling secured that I would be covered.
Even then, it was utter hell trying to get my laptop serviced under the warranty. They ended up giving me a replacement laptop with half the RAM (I told them countless times that I upgraded the RAM but they sent me a machine with less RAM than I originally had), bigger and clunkier than my older laptop with less features. The process took annoyingly long time, and I spent countless hours on the phone trying to chase down rude representatives. I ended up selling that machine on eBay as soon as I received it. I swore never to touch a Toshiba since then, and I never again even remotely considered another Toshiba ever again. I loath and hate having to deal with bad customer service. And the hassle just isn't worth it.
The value of your money is worth a lot more now than what it will be worth in the future. Technology is so rapidly changing that the high cost of the extended warranty that I currently pay for right now is worth less to me after a few years. The chances of machine failure after 1 year of use is small and probability is on my side that I have a machine that will last me at least a few years. And by that time, I will most likely want a new machine. That extra money that I didn't spend on warranty could have been put to better use on something that is more tangible than an invisible product like extended warranty. The hassle and stress involved in getting companies to honor the warranties also makes it worth less to me.
That's not to say that you won't be that unlucky person who gets a lemon. In fact, you may get 2, 3, 4, 5 lemons in a row. However, I think you have to put things into perspective especially when you browse these forums. These forums will attract more people with issues with their machines because that's the nature of these forums. People come here to resolve problems. So you will get a lot of people who tell you that AppleCare is required.
If you search on the internet, you may come across someone who has actually done some real number crunching to figure out how worth less these extended warranties are. Apple would NOT be selling these warranties if the failure rate of their machines were so great that they lose money by honoring these warranties. They sell these warranties because even after honoring them, the sheer number of people who have purchased these warranties who never use them before their expiration date is far greater than the ones who do.