The reason for all the different philosophies is because of the different uses, roles, and intents people have for their laptops. If you need or want it to last 4 years because you can't afford another any sooner or are like me and too cheap to buy much more often than that, then you should get a 4 year warranty. Why? Because it's so much cheaper than another laptop that it isn't much of a gamble. Simple math. Divide out the cost of the warranty across the length of time you'll have it and ask yourself, honestly, if you wouldn't just waste that money elsewhere if you didn't invest it into your laptop.
If you're pretty sure you'll buy another laptop in 2 years, and would rather give your existing one to your little brother or your mom when you're done with it, don't get a warranty any longer than 2 years. It won't do YOU any good, and if you're just giving it away, they can't exactly complain if their free laptop doesn't work 100%. They can choose to extend the warranty on their dime if they want it.
If you intend to resell it when you're done, a warranty that extends beyond the sale date does help.
If your laptop is in a safe place and is rarely transported, CompleteCare may be a waste for you. That's really your call. I'd still say to warranty it for the length of time you expect to own it. Most PC parts do, in fact, break in the first year, but there are people out there who have computers that make up the other 20% of hardware failures that occur later. Better safe than sorry, as the warranty is cheaper than most of those parts.
The stuff that us forum-goers help out most with isn't covered by a warranty anyway. People here will be glad to talk you through dis- and re-assembling your laptop to put in a spare part, but I doubt anyone here is going to help you pay for that part.