I also like many of the things others have mentioned. But the thing I like the MOST, is mountain scenery - preference for granitic glacial terrain (sheer walls, lots of lakes, U-shaped valleys). I like sweeping vistas. Forests are fine for a while, but I quickly get a penned in feeling. I spent most of my life as a mountaineer and technical climber-that is where my heart is.

I also like route finding and exploring off trail. I do not think I would do a lot of backpacking if all I had available was trail backpacking. This is why I like the Sierra and Wind River Mountains - very suitable for off-trail travel.