The Daily Caller has a good list of some of the more popular YouTube gun channels.
To this compilation, I would add Jeff Quinn at Gunblast, Mr. Guns and Gear, and Mixup98. Jeff Quinn is a hulking mountain man with a braided beard and a down-home style that is very much my kinda people; Mr. Guns and Gear provides informative reviews of all sorts of contemporary guns; and the guy at Mixup98 loves Tannerite and bump-firing.