The answer to the question depends on what your objectives and constraints are. If nothing else, it depends on how you personally rank "the best". There are plenty of avilable websites and magazines that rank MSc programms around the world.
For the U.S., for example. The best answer for you depends on a number factors. Here are some:
1. Money available
2. What's your SAT score/ are you a lagacy
3. Is location important
4. Is class szie relevant
5. Do you want to focus on industry or research work both during and after your program
From a more high-level point of view, there appears to be a correlation between general reputation, feedback from former students, and "career success". Stanford, Berkeley, MIT, Princeton, Carnegie Mellon...would all fit the bill. People who graduated are succesful in start-ups, research programs, or other major institutions, suggesting that the programs providede them with what they needed to become succesful - or at least didn't prevent it.