Pros
I work at AWS, and love the pace of growth and innovation, and the amazing AWS cloud services, as well as the transformational impact we bring into our customers' lives around the world. It's great to be a part of such awesome global force. I'm surrounded with highly competent, driven, yet super friendly professionals, who actually want to work all day, every day, to achieve results (yep, I find it rare and highly beneficial). I love the challenges we get to solve on daily basis - never get bored. Management sets vision and direction, and trusts that you'll take the initiative to implement it to your best judgement and ability (no micro-management). They ask what they can do to help every day. Arguably led by the best CEO on the planet, great leadership team, flat management structure. Great work/life balance - very reasonable performance expectations, giving you a chance to over-achieve them. I choose to work extra hours because I want to achieve more each week, like most around me - but it's not mandatory. Great compensation package.
Cons
Not an ideal place for under-achievers! :-) Fewer holidays and vacation days than offered by most companies - this is more than compensated by cool events you get to travel to throughout the year