Extended Service Plans are good but only on certain items.
I am one of those guys who sells extended service plans and I'm the guy who has to sometimes repair returned items. So when it comes down to what to buy an ESP on, I have a strong opinion on what to buy it on. These are things I think an ESP is good for:
1. First and foremost are PDA's, Pocket PC's all those handheld devices. These are the most troublesome devices i encounter. It seems like every Pocket PC i sell gets returned. They always have battery issues or some other hardware problem. So when looking at one of these devices a service plan is definetly a good thing to have. GPS units are much the same.
2. Cheap computers like Acer, Compaq and cisnet for example are computers that i always strongly suggest a service plan for. These brands in general put lower grade products into the machines that are much more likely to break down. I've seen the most problems come from these brands. If you don't want to spend the money on a service plan then go with HP.
3. On laptops warranty is a bit tougher to decide. I won't go into detail but my opinion is that you shouldn't get a service plan for a laptop unless your going to get an accidental plan as well. I don't care how exspensive it is. You can drop it if you want and get a new one. Make something up if they ask you what happened. They can't really do much about it.
4. Never buy warranty on a printer unless its more than $200. Your wasting your money otherwise because you can buy a printer for dirt cheap these days.
5. For iPods, if you have a case for one then don't bother with a ESP you probably won't need it. But I my self don't have a case for my iPod and have damaged it. In this case I wish I had bought an ESP.
6. Most other items you don't need an ESP for.
7. As well if buying a video card do not buy warranty because almost always you can get lifetime warranty if you registerd your card online. I got free lifetime warranty with the purchase of my Nvidia graphics card.
Thats about all I can say at this time. i hope this helps.