Hmmm...I can only choose 3 and they have to be what I think is the most important...well that's going to be difficult since sometimes situations call for different skills, but I'll throw 3 out there anyway.

1. Being able to make a fire with/without matches/magnesium stick and with good old traditional wood sticks.

2. Map reading and the natural sense of direction, or at least being able to pay attention to your surrounding and know where you are with/without a map if need be.

3. Common sense and the ability to use it under high stress situations. Common sense doesn't usually do you much good if you're panicking and stumbling through the woods.