We've seen quite a few diabolical alarm clocks. One of the cleverest so far has been the, a device that makes you get out of bed, locate the disarm panel, and type in a code to shut it down. It's awesome, but also a little expensive, starting at $160.
Take a photo somewhere in your house. It could be the bathroom sink. It could be the coffee pot in the kitchen. When the alarm goes off, you have to get up, return to where you took the original photo, and take a new one to turn off the ringing. If the photos don't match up, it will keep going off, so you can't cheat.
If you really want to be weird, you could use a photo of the front of your house. Your neighbors will wonder at the sight of you stumbling outside in your pajamas every morning to take a fresh picture of your home.
Sleep If U Can isn't entirely heartless. There is a snooze function and you can choose to skip the photo requirement if you're traveling or just simply tired of hauling your butt out of bed to turn off the alarm.