Your MBA experience might very well be the single most important investment you make in yourself as a professional. Given this, it is important that you spend those 1 or 2 years in the best possible program for you. This means you need to research, compare, and choose the program that offers the best fit for what you need.
This process is important on two levels:
1) You want to place yourself in the best possible environment.
2) Knowing yourself why your target program is best for you will actually make it a bit easier to get an offer, as you can demonstrate with specific details exactly why it is best for you, and why you will thrive there. Admissions officers like candidates that have obviously done their research, will obviously be happy in their program, and will therefore be happy alumni after they're done.
Selecting the right program means comparing what an MBA program has to offer with the strengths/abilities/experiences you need in order to achieve your goals. There are many resources you can draw upon to help you do this, sand you want to explore them as thoroughly as possible (and as soon as possible - don't wait until the interview when asked Why do you want to attend this school?).
The list that follows below includes some characteristics of MBA programs that demonstrate how programs differ from each other, and can be used to start your own research.
Obviously this is a good initial place to look when considering programs. What do you want to learn, and in particular, in which areas do you hope to be able to do deep dives? Exploring lists of electives is a good way of seeing which programs offer the education you are looking for. Moreover, how are the courses organized? If you want to go into HR management post-MBA, it might be wise to study organizational behavior before your internship. Is this possible? What for the banker aiming to go into consulting? Obviously the MBA offers the typical basket of skills, but will one program make you choose between important electives, where another might allow you to take both? As you consider the ideal courses for you, and even their timing or availability, some programs will rise to the top, while others might eliminate themselves from contention.
Other Academic Opportunities
This section is necessarily broad, because there are so many possibilities to consider. Here are just two:
a) Capstone (experiential) programs: are they offered, and if so in the industry or even with a company that will add value to your experience?
b) Overseas trips or study experiences: can you build networks in the places you need to? How much choice do you have in choosing where you might study, and what you might do there?
Clubs and Extra-Curricular Opportunities
What personal goals have you established for your MBA experience? Do you want to be in a place where not only you but your entire family can benefit from the international experience? All programs have some variety of Partners Clubs or events for family members, but further research will help you to find the programs that are ideal for you. What else is important to you? If you desire to be in an Asian Marketing Club, a South American Business Club, or to even create a new club, you'll find quickly that not all programs are created equally.
Who will be teaching the programs you wish to attend? Some professors offer benefits over others, such as industry or region-specific experience, a network in a certain field or a research interest in a particular and focused area. As such, this area of your MBA experience should definitely not be overlooked.
The Characteristics of the Program
Do you value teamwork, or hands-on learning? Again, not all programs are created equal. Are you interested in learning via case studies or lectures from professors? The difference in the experience here is substantial. Are grades given to project teams, or individual members? How is in-class participation graded? Are courses graded on curves, with only (for instance) a fixed number of As offered to students? This will define, in many ways, the amount of competition or collaboration between yourself and your classmates.
The School's Reputation
By this I don't just mean "is the program known for its strength in marketing or finance". This is of course important, but in addition, does the school have a reputation for helping students change careers? Has its graduates been successful gaining employment in certain industries or functions, or in certain parts of the world? What companies come to recruit on campus? Is the brand or name-recognition of the program high in your own country? If so, it may help to open valuable doors for you.
The School's Mission
What does the program exist to do? What kind of leaders are they aiming to create? Does this agree with what you want to do in the future, how you see the world, or how you aim to change yourself?
Atmosphere / Culture and Other Students
This is why it is important to visit campus and talk with alumni of the program. Because without doing both, it is hard for you to truly envision whether this school is where you want to spend the next 1 or 2 years of your life. How do students interact with each other in class, on campus, and in social events? All schools attempt to forge bonds amongst members of their student body - but not all bonds are created equal. In terms of the other students in the program, this is on one hand very obvious, and on the other difficult to figure out. You may be able to access demographics of previous classes, but you won't know more about your own classmates until you actually choose a program.
The Location of the Program
This is not about the weather. Rather, what opportunities does the program have regular access to? The proximity of a few top Californian MBAs to Silicon Valley is one obvious example, although it should be noted this entrepreneurial region is visited by MBAs from all over the US (let alone other countries too). What kind of opportunities are you looking for in your MBA, and beyond? If your goal is to land a job in a top Canadian company, than Rotman, Ivey or Schulich might inch closer to the top of your list. If learning Spanish or French as a third language is of value to you, programs in Spain or France might work better. If, on the other hand, your goal is to become a specialist in Asian business, a program in China, Singapore, or even Japan might fit best.
For More Reading
I'd suggest looking through my delicious links. I have almost 20,000 of them (!) and the most popular tag is "MBA". Search for the following set of tags: MBA+fit and I'm sure this will put you in the right direction to kick off your research. Add a school name (for instance Booth+MBA+fit or Stanford+MBA+fit) to specify articles for one particular program.