Having work experience will always help your CV and most of the MIM programs do require atleast 3 months to 1 year of work experience. For St. Gallen, IIM Ahmadabad you need 2 years of work experience and they are in the top 10 MIM programs. Most MIM program will have the option that you gain some sort of work experience during the program.
For Example, HEC paris you have the option of working for 37 weeks and then have the foundation year followed by the main program. some students don't join the first year if they have adequate work experience. Other universities have an internship after the program is complete.http://rankings.ft.com/businessschoolra ... ement-2012
you can refer to the above list for rankings.