I know there have been many threads about cheesesteaks in the past, so here is my 2 cents.
I haven't been able to eat a commercially made steak since 1994, but the memories are still there. Without question, the best I had was the one from Jim's. The right combination of good bread, spices, onions and of course steak. Sure, you shouldn't go there if you are concerned there is too much grease, etc.
But, if you are willing to thumb your nose at your cardiologist, Jim's is the place.