We have a prominent incline in front of our hangar, so a tug is absolutely needed, we are very happy with our SUPER STRIKER electric tug from NW Manufacturing.
Here
It works on most any corporate aircraft with a single nose wheel, turn limits are never exceeded because the nose wheel doesn't need to move at all, it swivels freely on the dolly, so you can make 90 degree turns if needed. Has plenty of power to get our TBM up the hill, and makes 0 noise, I think ours was just under $5000.
Others on my field have also purchased the Robo Tug which is a little remote control device, they are great for stacking a hangar if you are alone, kind of pricey though at around $10, 000.