Here is my $.02 to this question that is frequently asked on ATV forums.
All brands of GPS's will track and allow you to track back, save the track, etc. All brands have similar accuracy depending upon price range. IMO the larger the screen the better. Which is best depends upon what you want to do. If you just want to leave a track so you can find your way out, any will do. If you want to load maps, etc on it then I think the options narrow quickly. That brings me to my recommendation.
I think for ATV riding your best option is Garmin and not for the reasons I mentioned earlier. Garmin is the only brand that you can get a lot of free maps for at places like gpsfiledepot.com. They have excellent Topo's for all states, free ATV maps of the popular riding areas. The reason there are so many free maps for Garmin is that a few years ago a guy, Stan, in Poland figured out how Garmin makes their maps and wrote a program that you can use to make them. For full disclosure I am one of those people that makes Garmin maps (mine or free). You can go to this thread on here and see a description of my WV ATV Trails 2013 Map.
http://www.polarisatvforums.com/forums/atv-trails/47042-released-new-wv-atv-trails-2013-map.html
As far as which Garmin that depends on your desires and wallet. As mentioned the 62 is good as is the Oregon. The Montana is the top of the line and has an incredibly large display that can be seen in full sunlight. A LOT of people use Nuvi's. You can load Topo's and my maps onto them. They do track and you can get the tracks off to view on your computer or Google Earth. The Nuvi's have large screens. If you already have a Nuvi try it before you buy a handheld.
Not intending to piss someone off who has purchased one I would not recommend buying a Garmin with the pre-loaded Topo. They are 100K topo's and you can get much better 24K topo's for free at gpsfiledepot.com. Also, everyone I know that has a camera model does not use it. The camera faces forward and has not lens cover and is always dirty. They all have duct tape over it. We just carry cheap cameras around our necks.
Hope I did not confuse you, it is not an easy decision.