Ouch, tough one. I think there are eight or nine Atv's that would be awesome for what you want to do. The question is what do you want to do.. It's been a while since I shopped around so you'll have to really do alot of that until you find exactly what feels right to you. But for me, I would look closely at the Polaris 400 & 500 with independent suspension. Having been in some bad situations in the rain and mud and running out of gas I would tell you to avoid the big boys, like the Twin Cylander 700 and the newest race to the biggest and badest. Stay modest and get the cc's that you actually need for the job. I loved the Honda 300 4x4, but then they stopped making it. What a shame, that was the best ATV you could get in my opinion. All day on one tank of gas and it would out climb, and out run a lot of the competition.
I love my Honda 450 ES.It's a 99 with over 8000 km's on it.It is 475 cc.I hauled out an 1100 lbs moose last year.I have a 2500 Warn winch on it.I bought a new Kawasaki 360 Prairie 4x4 last fall.It's a great bike as well,but an automatic and I don't reccommend hauling alot with it.I've had to replace the belt already,and it just has 1200 km's on it.Belts are $100 a pop.
Oh yeah I forgot about the Prairie, I remember looking at that one pretty hard, can't remember what led me away from it though. As far as honda think what led me away from them was really only finacial reasons. There is no argument in my mind that they have the most dependable machines, I just couldn't afford to go that route.
Understanding wind currents and thermals in hilly, broken terrain can often be incredibly frustrating. I've found that collecting and storing milkweed seed pods during the late summer has made me a better hunter in the bluff country that I hunt. These little feather like seed dispersers will float on the lightest of air currents and will show you what the wind is not only doing right at you're location but more importantly down range. I like to use the off season to float them...