Pros
Amazon still feels like a startup in someways, in that everything is moving quickly and there are many opportunities to make a difference. I have felt empowered at Amazon to make impacting decisions that at other companies may have been slowed by bureaucracy. Amazon is not perfect; however that results in opportunity for you to fix the imperfections and get recognized. There are many diverse job roles at Amazon and many different business groups and you are able to move to different business groups fairly easily if you perform well in your current role. The people working at Amazon are smart and most seem fairly happy. The company is still growing fast and the total compensation which includes generous stock awards is very competitive.
Cons
Amazon may not be the place for everyone. It is a challenging environment and for some job roles the workload can be demanding. The benefits could be better, they are adequate at best. Your annual salary for the first few years can be on the low side (before your stocks vests).