I actually got a lift for my ATV. It works off the winch. It works pretty well. When you release the winch, it comes off the front of the ATV and lays on the ground. You drag the deer on it, buckle it in, and retract the winch. The gizmo then picks up the deer and sets it on the front of the ATV.
Here is the one I got:
http://greatdayinc.com/products/atv-accessories/powerloader/
I did have a cart but I found there are places that it is hard to maneuver a trailer when retrieving a deer that I can easily drive an ATV up to. The down side is that it runs about $300.
Thanks,
Jack