I work for Google, and there *are* some people who work insane hours every days, but that's not really typical. In Mountain View, a large percentage of the population leaves around 5 or 6. Sure, some people work late every day, but they're usually the same people who arrive late every day. Google isn't really the sort of place that values Spending A Lot Of Time At The Office. People are judged by what they've accomplished, not how many hours they were around looking busy.
If anything, the problem with Google is that there's *so* much cool stuff going on--you know, if you have a bit of free time, then the temptation to work on cool project AAA or BBB can be hard to resist :-).
Most of my Microsoft friends work longer hours then I do, but I can't claim that they're a representative sample.
As for the Seattle vs The Bay Area debate--you do know that both companies have offices practically right next to each other in both areas, don't you? MS's Silicon Valley campus is under 3 minutes from Google, and our Kirkland office is probably only 5 minutes from MS on a good traffic day. I work in Kirkland, it's a nice office, and we have a lot of fresh college grads from around the country. If location matters, then talk to your recruiter (for either company), and I suspect they can work something out.
All things considered, I suspect that the original poster would be happier at Google, but I'm kind of biased.