I hate being awakened suddenly, so when I use my mobile phone as an alarm clock, I usually choose something soft and pleasant as alarm signal. Right now it's Blue Öyster Cult's Astronomy... though truth be told, the vibrating of the phone gives off more noise than the alarm signal itself
As for music to get me going and prepped for a new day, that varies depending on my mood. Sometimes I like 'em hard and fast, and Elite by you-know-who (no, not Voldemort) gets played a lot in these cases. Sometimes I'm in a more thoughtful/tired mood and that's when something calm and/or melodic fits best, like the previously mentioned Astronomy (cover version by Metallica works too, if a bit more rocked out), Don't Fear The Reaper or I Love The Night (best when it is still dark) by the same band. Then there are those mornings/days when the world sucks, and Dreadnought or pretty much anything from early Metallica suits best.
