Android: Fiddling with your phone in a groggy, half-asleep state is difficult. To make it a bit easier, Wave Alarm allows you to silence your alarms by waving your hand over your phone.
The app uses your front-facing camera to detect hand movements. Just make sure that your phone is sitting face up and within arm's reach and you can shut it off with ease. Whether or not that's good for your morning routine is up to you.