What do you do with yours?
Everything! This is the one device that lives on the counter -- I didn't even have a food processor for years. Even now, I almost never use the big one -- my Kitchen-Aid and mini chopper handle just about everything I want to do.
Regular baking, doughs, etc., of course. I burnt out my first one and had to upgrade to the bigger model I made so many heavy bread doughs with it. :-). Pizza doughs for family pizza night!
Pasta roller/cutter: makes it massively easy to make fresh pasta. Make pasta dough using dough hook (basically, flour and eggs). Let rest 20 mins or so. Use roller to give a little extra kneading (roll, fold, roll, change thickness one click, repeat). Let sheets dry slightly, change to cutter, cut. I have to say, the ratio of "wow" factor to unit of effort is higher for pasta than anything else -- it is the one thing that seems to impress the hell out of people, and it is just sooooo easy with this thing!
Shredder: best use is for latkes -- I put both the potatoes and onions through. But any veggie you need sliced or shredded.
Grinder: every once in a while I decide to grind my own meat for something, e.g., I want to make chili with a thicker grind, or like a few weeks ago I wanted to make pork lettuce wraps but the ground pork was ridiculously priced and I remembered I had half a tenderloin in my freezer. This would be awesome if I hunted or had other access to game (I did use it to make venison chili when our neighbors gave us a hunk of meat they had hunted).
Also second the vote for marshmallows -- those need to be whipped for a long time with very hot stuff, and it is really nice to be able to just turn it on and let it go. (Also high on the wow-per-unit-of-effort scale -- really kicks the homemade cocoa mix Christmas gift up a few notches.
The only thing I have not had luck with was the pasta extruder. Oh well. Plenty of other options.