What college should i go to if i want to be a mechanical engineer?

There are quite a few universities that are great for Mechanical engineering.

One of the most important factors (along with the posts that have been mentioned) you should think about is the stuff you want to work on. Is it cars? Is it oil? Is it factories?
You should choose an engineering school that is near the industry you want to get into. For instance: University of Michigan is a great school if you want to study Automotive(cars) as Michigan is the automotive capital of the country.

Pay keen attention to what you are interested in. This goes a long way to making you a successful engineer.

There are many universities that offer mechanical engineering as a field of study. For me, the decision was based on the costs involved (tuition, room & board, and transportation). I chose to attend the best university that I could afford. This meant attending a small local university and driving to and from school, as opposed to attending a large university, staying at a dorm, and walking to and from classes. The university you attend must be EAC/ABET accredited, which I believe most are. I don't think it matters so much where you go to university as much as what you do while you're attending the university. The two big things you'll want to do are focus on your studies to get good grades, and seek-out internships with companies so you can gain work experience while earning money at the same time.

You can easily find this information online. eg.

http://www.collegefactual.com/majors/engineering/me-mechanical-engineering/rankings/top-ranked/#

or http://grad-schools.usnews.rankingsandreviews.com/best-graduate-schools/top-engineering-schools/mechanical-engineering-rankings
or http://www.topuniversities.com/university-rankings-articles/university-subject-rankings/top-mechanical-engineering-schools-2015

Remember that Mechanical Engineering is a very broad field and you might want to find out what interests you in it. For example, ME can be further categorized into Oil and Gas industry, Energy, Mechatronics, Automotive, Aeronautical, Food Industry, Industrial etc. Investigate your interests deeper and use it to choose your colleges and steer your career.