Pros
Perks, food, successful company, some cool products, resume builder
Cons
Your time at Google is entirely dependent on the capabilities of your manager. I worked in MTV for 4.5 years and I've never been at a place with more inconsistent quality of managers. I reported to 6 managers during my time. A few were great, but others were horrifyingly bad. Had enough with my last manager, who was self serving and not well liked by his group, yet the company did NOTHING to remove him. Decided to chart my own course by joining a startup that was more human focused. Have not regretted my decision whatsoever. Much happier now. Too many Google managers are often the victim of their own hubris + lack of real world experience. In 2005, Google was a place where you could change things and make decisions quickly. Now, it is a place to be a cog in a giant profit machine.