That's easy Chris, one pistol that comes to mind is one that I shoot in 50M Free Pistol matches.
It is the Morini 84E; because of the hand enveloping grip; (See it here):
http://www.morini.ch/product_det.php?id=7
It's really hard to hold with two hands. I guess that goes for all pistols with
an anatomical or wrap around grip. These grips are designed for single-handed
offhand match shooting. Most modern 50M (Free) pistols have the
wrap around grip; such pistols are made by Hammerli, Morini and Pardini.
Tony