Last summer I did an internship at, ummm, Steve Jobs's current venture. It wasn't a good fit for me, but that had nothing to do with the size of the company. The position simply wasn't a good match for my skills and experience. I was offered a full-time job as a result of the internship, but since it wasn't a good match, I turned it down.

That said, my feelings about the internship had little to do with the size of the company. The perks of a big-company internship were great, and you can meet a lot of other interesting hackers through a larger internship program. Also, all my previous jobs were at much smaller companies, so it was great to experience life at a large tech company first-hand. Life at the large company wasn't really any different than life at smaller companies.

I would suggest picking the job that interests you the most, based on the team or the project you'd be working on, and the quality of the individuals you'd be working with. The most important aspect of an internship should be the work you do. That will be the most important factor in how much you like it, and that's what you can show off in future job interviews. Plus, internships often lead to full-time jobs, and you won't want to make that decision solely based on the reputation or size of the company.