I have also had a very positive experience with Amazon after doing two internships with Amazon (one of Seattle and one out of Dublin). One of the few companies around that actually allowed me to design, think and be critical rather than just being cast away into some needless intern project. At my school, they tend to hire as many people that meet their bar rather than setting a quota which is probably why it seems that they are always hiring.

I'm comparing to two other internships - two at a theoretical physics institute in Waterloo and two with Bloomberg in NYC.