Wondering what test you should take? Read this article for some differences in the two tests: http://www.theglobeandmail.com/report-on-business/careers/business-education/mba-aptitude-tests-battle-it-out/article2367432/
The ILLINOIS MBA accepts the GMAT or the GRE. Many joint degree students (students receiving another masters degree) often take the GRE since they need it for their other program. This allows us to have diverse backgrounds in our classes. Students applying to many programs usually take the GMAT since it's more widely accepted in business schools.
For information on the GMAT please visit www.mba.com.
For information on the TOEFL please visit http://www.ets.org/gre/.