Microsoft

Prestige. Having interned at such a renowned company makes it much easier to at least land an interview for any other CS-related job.

They attract great talent from all over the world. No matter how smart you are, you will definitely meet people like you, and even better, being able to learn and gain experience from them.

They focus too much on their technologies.

It may be the best place to specialize in MS technologies, but if you want a more general experience, that will be restricting.

There is a general atmosphere and hype inside the company that "Microsoft is the best," which gets tiring after a while.

Combined with the facts that MS is less diverse in their projects than other tech giants, the huge bureaucracy, and the large number of ineffective managers unable to give the right feedback, I couldn't think of myself working there for more than 2-3 years.

In conclusion, working for MS is great to launch your career, but working for a smaller, newer, and faster-developing firm is much more interesting.

Give more incentives to employees, more rewards, and generally make work more challenging for the competent ones.