Ask YC: Internet Startup or Big Powerhouse for a summer internship?

Hello YC! I'm a current UC Berkeley computer science student in my junior year (and loving it), and I've been mulling around this question in my mind for the last couple of weeks: Should I spend my summer at a small (30 people) startup or at a reasonably big (1000 people) CS/Art company? I have an offer from each of these categories, the pay is the same, and i'm pretty sure both would be a great working environment. What I'm left to decide is which one to take, especially considering the experience and education I would get in each sphere.

I really can't decide, so I'm hoping for some opinions from the hackers here at YC news. Which would you choose?