I'm a new grad (June 2013) with competing offers from Amazon and Qualcomm. The financial situation is near identical between the two offers. Also, I like both San Diego and Seattle, so that's not a factor.
I'm most concerned with:
-Working with smart people
-My own career
-Enjoying my life
My gut feel - At Amazon, I'd probably have the opportunity to learn a lot more. I get to choose my team which allows me to learn exactly what I want to learn. I also feel like Amazon is a very respected brand for software engineers, and having this on my resume might do more for me than Qualcomm. My Amazon interviews were rigorous, which leads me to believe the people there are smart.
On the other hand, I've heard bad things about Amazon's work life balance and frugality, and I realize I'd have a more care-free time at Qualcomm. I do enjoy having a life and doing things in my spare time.