Georgetown is one of the oldest standing SMPs with one of the best track records. They report an acceptance rate of >50% the year you are doing it and 85% overall. That, for those with mediocre academic records, is somewhat surprising. That being said, their entrance requirements are also pretty high.
Drexel and EVMS have also been around a while but Georgetown has a stronger name nationally (which may help if your state school isnt in VA or PA). EVMS reports a 73-90% 1 year acceptance rate but I do feel they send a bunch of kids to DO schools (and the Georgetown entrance requirements would make you competitive to many DO schools). I cannot tell you the acceptance rate for Drexel b/c I do not know it.
If I were to rank them it would be Georgetown, EVMS then Drexel but this is somewhat arbitrary. All may give you the tools to get into medical school