View system that allows me to look around easily, move head position. AH's is the best I've ever seen.
Nothing else even stands in the same room IMO.
Stickmapping/keymapping system that pretty much allows you to do anything you can imagine.
Flight modeling, although tis not perfect perhaps, its IMO better than anything else available.
Community, As Teddy Roosevelt said once in reference to the USA, a bit of foam on top, some dregs on the bottom. But on the whole a good solid barrel of beer. A few frothy squeekers on top, and some bitter whiners on the bottom. But for the most part a great community.
Wide range of planes, GV's to play with, of course being who we are we'd all love to see more.
Planes are free, server access may cost us 15$ a month. But thankfully HT & Co are not greedy.
They could have decided to charge us by the plane. I hate to think about what that would have cost me.
And I can crash one plane after the next and not worry about racking up a huge bill.
So for all you do, but especially the free planes Thank You Hitech & Crew!