Pros
Salary and benefits at Microsoft are great. There are tons of perks for working at Microsoft that aren't well known outside of the walls. Lots of great people to work with. Occasional project that is really fun. Very challenging place to work and you learn a ton.
Cons
Over the years Microsoft has really scaled back on every front. Office politics are extremely high. Lots of people put into management positions that can't manage. Extremely high turnover rate because of poor first line managers. (They stated this in my New Employee Orientation) People hired that are incompetent but somehow continue to get raises. If you want to get ahead, the best thing to do is throw someone under the bus. Microsoft wants everyone to be the same cookie cutter person but they claim to celebrate diversity, so beware if you don't fit their mold. They say they have great work/life balance. If you choose to do a modified work week (4 days - 10 hours each) be prepared to go backwards in your career. It is looked down on and you will be told you are fine, but come review time don't expect anything good.