Longer warranty doesn't mean something is more reliable. It doesn't mean your "data is protected."
In all my years of buying hard drives (close to 200 drives) I've had the best luck with Maxtor. I only had one Maxtor out of about 50 go bad. Maxtor replaced that drive and it is still going strong. Every other brand I've tried has had worse reliability, regardless of warranty.
Also remember, a longer warranty isn't going to "protect your data." If a drive goes bad, you data is toast, regardless of whether it is under warranty or not. The key to protecting your data is to backup your data the first instant you get any indication of possible hard drive problems. This is why having multiple drives in your computer is critical. I can ghost image my boot drive in a matter of about one hour, provided you have another internal drive.
Also having another computer, or a friend with a computer, is a key to retrieving your data on a failing drive. For example, let's say your boot drive goes south and your OS won't boot. Many times you can't reinstall without erasing the entire drive. What you do is open your computer, pull the drive and connect to another computer and backup the data, provided the drive isn't actually physically shot. This is where a portable drive enclosure is nice. This is the key to saving your data. This is the one step computer repair stores will charge you an arm and a leg. Doing it yourself is simple. Just make sure your friends computer has good virus software, because the reason your drive "crashed" is probably more because of software problems than hardware problems.
Finally, if your drive is going bad physically, clicking and stuff. Sometimes you can nurse it just enough to get the data off it intact. This is where having a second computer and portable enclosure are key. I've done this many, many times. Sometimes halfway through the process, it starts clicking and failing. I turn it off, turn it on again and sometimes you can get the rest of the data.
This even works for notebook drives. All you need is a notebook to EIDE converter which allows you to connect the drive to desktop computers. I got one from Geeks for around $5. It has proved invaluable a couple of times.