Interesting thread. I think the problem is defining "remote." Someone mentioned that the ability to fly in a plane or helicopter to a location makes otherwise "remote" places pretty easy to visit. So, would that make wilderness areas (in the US) the best candidates because you can't fly into them (as a private citizen) and have to use human power to travel to them?
As far as places with dwellings, I think parts of southwest Colorado and the four corners region are pretty remote in the sense that you're very far from even medium-sized cities. Take Telluride, CO: 360 miles to Denver, 400 miles to SLC, 300 miles to Albuquerque, 500 to Phoenix. The closest "city" is Montrose, CO, which is still 70 miles. It's 45 miles before you even hit a stoplight. 70 miles to find a Walmart. That's pretty "remote."
As far as the most remote place I've ever "felt" in Utah, it would have to be either Canyonlands NP or the Canyons of the Escalante area of the GSENM. Come to think of it, The Maze District of Canyonlands NP is awfully far from civilization and very difficult to travel through.