Practically every University's M.B.B.S degree works out differently, this is easily shown by the number of years taken to finish the Med Degree.
As Aussie said, there is no "best" med school, not even Harvard can be considered the best. The most important thing is for you to fully understand the needed requirements for that uni which you plan to take your Med degree at.
I think its more or less your preference of which hospital you wish to head to for clinical training rather than the uni. Not to mention, i.e. for UNSW they usually hold most of the lectures and tutorials at your assigned Hospital, not on its usual campus. Also remember this degree requires long periods every day.