Pros
Great for your resume. You will work with some very talented people. Project to project things are very different. If you find the right managers, the right teams, then you can really work on some great games. The knowledge sharing and the skill sets you can learn are great. There is room for one person to make a difference on some teams, but it is rare.
Cons
Career advancement is very limited. Salaries aren't as good across the board as many other places. Zero room for ownership or making money after the product has shipped. The worst part is you feel this weight of the company and like most large organizations you just have to tune that out. The problem is there really isn't much in the way of kaizen, constant improvement, happening on a lot of the teams. It can be more intensely political than is neccessary.