Best Buy and HP are on my I'll-take-my-chances list. When I've bought warranties from either, they've failed to honor them in more cases than not. HP spare parts are also sufficiently plentiful on eBay and I've gotten to the point where it's worth my time to just swap the parts out myself when something goes wrong. Admittedly this is atypical for the average consumer (especially when it comes to iPads and similar), but it's true at least for me.
Cell Phones? Asurion. Always. I've never once had an issue with them; I pay my deductible and I've got a phone on my desk at work the next day, every time. THEY are worth it. Yes I know that this is insurance, not a warranty per say, but ultimately it boils down to semantics insofaras Asurion gets paid monthly through my cell carrier while an extended warranty is a one-time payout.
Origin PC is another company whose warranties are worth it. Perfect support, perfect track record with replacement parts, and they've worked with me every time, without exception. I'll by warranties from them any day.
Tablets? Well, mine is a Toshiba, a company who's also been historically atrocious with warranty related matters in my experience, plus the tablet itself is sluggish and moderate-at-best quality so the device itself doesn't justify it for me personally.
This does raise a tangentially interesting business question though: we all know that businesses make a mint off the warranties and thus push them in order to bump the profit margin on the sale. I get that, and I'm okay with it. The problem then becomes the fact that it gives incentive for device prices to remain artificially high. If the device is higher priced, companies make more money. It justifies warranty purchases (also at higher prices) in many minds due to how expensive the device is. Now in the case of Apple specifically I'll give them a certain level of a pass on this because they are well known for honoring their warranties very consistently. Everyone else...not so much.
Thus, My original premise stands: certain companies make it worth it because there's actual peace-of-mind involved. I don't worry about my laptop breaking; I know Origin has my back without question. I don't worry about my screen cracking, Asurion will see to it that I can make calls tomorrow by noon. My Toshiba tablet? I have peace of mind knowing I'm screwed if the tablet breaks, as opposed to knowing I'm screwed if the tablet breaks AND I have a hundred bucks in Toshiba's hands whose only redeeming factor is having some underpaid foreign support representative informing me I'm screwed and my warranty doesn't cover whatever-happened-to-my-tablet.