Pros
Good hours, nice benefits, random niceties like bbq, games, free food. People switch nicely between relaxing when there's time to working their butts of when needed, most co-workers seem genuinely interested in doing a good job, helping both their own team and the departments as a whole. Concierges, we have them and they rock, they help deal with all sorts of stuff including running errands, taking cars to the shop, etc.
Cons
We're growing a lot, so it's getting a little crowded, but there are plans in place to fix the space-issue. When I say crowded I simply mean that it's nice to have headphones to shut out the noise and chatter, though most of the time it's not that bad. No free snacks. Parking is tough if you're a little late due to us expanding.