The argument could be made that front would be the place to start if you're only getting one. When driving forward up-hill your weight shifts from the front axle to the rear so you're more likely to loose traction on a front wheel first, and so loose all help from the front axle.
But honestly, if you've only been off-roading a year, spend more time with open diffs to really get a handle on how to drive. It forces you to become a better driver.

 

I completely agree. You need to learn to drive the truck off road and find out what it can do stock before you go dumping money into for off road mods.

 

My grandfather was a hillbilly and never owned a 4wd vehicle nor a winch. I remember one day when we were going down some God forsaken trail looking for a lost cow in a bone stock 2wd Ford F250 with an open Diff and mismatched tires and we came along some city folk with pretty decked out rigs trying to get up a somewhat nasty little section of the trail. Lifts, aggressive tires, winches and I know they had lockers at least in the rear of a couple of the trucks, but they were picking poor lines and bouncing and bucking halfway up the climb spinning tires and backing down to try again. We waited patiently for a few minutes watching them hack their way part way up only to achieve utter failure. My grandfather had enough and asked if we could pass and we received more than a few smirks and snickers as the "hotshots" let us pass. My grandfather drove straight up the same nasty section of trail and we continued on our search for the stray cow. I looked back as we crested the top and their sh*t eating grins were replaced by open mouthed looks of disbelief. I was very young at the time, but that "lesson" has had a profound impact on my off road driving style. These goofballs were out trying to conquer a seemingly impassible section of God's country. Man and machine against nature. We were looking for a cow.

My grandfather knew how to drive. God rest his soul.

 

this is why my first mods will be protection: sliders and a front bumper. maybe a skid plate.

i drive my disco everyday, so i want to protect it as i push its limits.

after that (probably once this is my 2nd vehicle) will come to the lift, differential mods, etc. i'm totally jealous of peoples rigs on here, but know i'm not ready for such a beast.