I run Schwalbe Marathon on both my bike and my wife's bike. Never had a problem mounting them with my bare hands.

I had the devil of a time with Gatorskins on my hybrid. In the end I used the dreaded tire levers.

A little tip:

Before you mount the tire with the tube in it and slightly inflated, run your finger wetted with dishwashing soap all along the edges of the tire. Makes a lot easier for the last six inches of the tire to go over the rim and into position.