So you're shopping last minute and decide to be extra generous and buy the big-screen HDTV, or maybe the DSLR camera I've wanted for a long time...oops, sorry. That's not meant for you.

In the excitement of the moment, the store clerk begins to rattle off the extended warranty options he recommends for purchases like yours. Of course he does; that's how the store makes money on electronics that keep falling in price. Should you bite?

The short answer: no. Consumer advocates have long said most warranties are not worth the peace of mind they supposedly bring. You're buying an insurance policy to cover repair costs should the item break after the manufacturer's warranty ends. But Consumer Reports and PC World say tests of hundreds of products indicate more are reliable and fairly durable every year. And if they should need repair, the cost is often on par with what you've paid for the warranty, according to Consumer Reports.

You're better off spending the time researching which brands and models have performed best in consumer tests than spending extra dollars in a gamble that the one you choose will have problems.

When plasma and LCD HDTVs were new and the prices were sky high, Consumer Reports recommended opting for extended warranties because the technology was untested and the TVs cost so much. But the prices have dropped, and Consumer Reports' latest reader survey finds that in the last three years, HDTV owners report few problems with their TV sets.

So CR now recommends saying no to TV warranties. (The magazine makes one exception, advising consideration of extended warranties on rear-projection TVs, which are three times more likely to need repairs than other TVs.)

Meanwhile, J.D. Power & Associates' 2007 Major Home Appliance Survey of white goods such as dishwashers, ovens, and washers/dryers finds most so reliable that no warranties are recommended on those purchases either. In the first two years of ownership, one-tenth of owners report problems with their appliances. And most of those problems can be fixed by reading the manual or seeking help on the web.

This holiday season, your best bet may be to do what CR Senior Editor Tod Marks recommends: Put the money you would have spent on an added warranty in the bank so that you'll have it in case you need to repair your latest electronics purchase.