
Back in 2005, I was excited about the Web and I thought working at large Web shop like Amazon.com would be fun. I also wanted to try living in Seattle for a summer to see what it'd be like to live further away from my family.
Anyway, I found it satisfying to work on projects that actually interface with Amazon's customers. I can't say that's the case for everyone who works there, but I feel I got lucky. I also met a lot of smart people and enjoyed reading the various mailing lists and IRC channels.
However, unlike most tech companies, the food in the cafeteria is terrible and not subsidized. The company is quite frugal. And like most large tech firms, the pace of development is slowed down by layers of bureaucracy.
Overall, I'd say Amazon is a good summer tech intern experience, but I didn't seriously consider it when seeking full-time employment.