Pros
They pay well and of course have good health insurance. There are a lot of young people (this can be a pro or a con, depending on what you're looking for), and the campus is beautiful. Many people have their own office or a single office mate.
Cons
There's an expectation that everyone is working really long hours and being continually overly busy. This leads to a closed-door culture (at least, in the building I work in), where you feel like you can't interact much with your coworkers because you're probably interrupting them. If you're in software, the two languages we most use are used almost nowhere outside of this company, so the skills don't transfer. There's a huge amount of (paid) training required, most of which is not useful outside the company, and which, in many cases does not actually prepare you for your job. There's very little support between people on the same team, so if you're looking to understand something (because you're new) or get walked through a workflow, it can be very difficult. Despite their huge profits, they don't bother to have little daily benefits, such as snacks in the break rooms or subsidized lunch. It makes it seem like the employees are not really valued. Also, many of the longer term benefits (401k matching, "shares" in the company, better vacation) don't kick in until you've been at the company for much longer than the average person stays.