My Bully Bull grunt tube, it is cumbersome and a pain to pack around but you can make a canyon light up with bugles using that thing. It also works good for calling in other hunters if you're looking for a good conversation.

My Brunton Epoch binoculars, they get used more than anything I own for the outdoors and the best thing was I scored them on ebay for $475.

My Leatherman has to go on this list as well, I dressed three elk with it one morning when I left my regular knives in the saddle bags and you feel like Macgyver whenever you use it.