Pros
The best part about Amazon is its focus on ownership. You really have the opportunity to contribute to your project, and in more ways than just "here's the feature, code it up". You get to think of how you want to improve the project and are encouraged to do so in anyway you can. There's not much to say about compensation and benefits. They're around average, but I still list it as a pro. Free snacks in the kitchen.
Cons
I can't imagine having less work-life balance. We don't get sick days, so when you get sick you come in to work and give whatever you have to everyone else (and they return the favor, hooray!). They don't bother mentioning it in the offer, so it comes as a pretty big shock when you get sick - "Oh, by the way we're the only major company ever to not offer sick days." Of course you can take some of your very limited vacation days instead if you want (that is, if you even have any saved up). Another perk they don't tell you about: being on call. They don't have Ops teams here and barely have Customer Service, so as an SDE you get to play both. Getting paged at 3am for issues beyond your control is not a lot of fun, and neither is responding to customer issues all day with "this behavior is expected". And I hear if you're in Seattle, it's even worse (as in, even less work-life balance). God help our Seattle brethren.