Pros
There are amazing healthcare benefits. I have never paid out of pocket for any medical expenses and I've had a baby along the way. We joke that our baby was "free". Kids just out of college have no idea how huge this health benefit is: free prescriptions, check-ups, self referrals to specialists. The company is stable for now and there are no worries about where your next paycheck is coming from. You get to work with amazingly smart people and take on difficult challenges. You are never bored and always feel challenged by your job and plenty to keep you busy.
Cons
The external reputation of the company is bad which can lead you to question why and how you can manage to work there if you only look at the outside picture. There are many cultures inside the company, some of them dysfunctional or with awful work-life balance. Just as in any big company there are egomaniacs and selfish types whose primary objective is to climb up the career ladder and make partner. The cafeteria food isn't that great and it isn't free like at Google. The company has to really make up time in the Internet space, even though IE caught up, the software as a service space is still there to figure out.