For personal protection in the woods I typically just carry my Glock 26. It's lightweight and small, reliable and easy to maintain. In Colorado we no longer have grizzly bears, so my "threats" really include the following:
1) black bears. Not a big threat, generally don't mess with people, and would probably be deterred without needing a HUGE-honking pistol. I don't really consider them much of a threat, unless you get in the way of their cubs, or catch them in the wrong place at the wrong time. I've seen lots of bears out here, and they're just as happy to go their separate way from you. Black bears don't typically prey on large animals either, so we don't look like we're on the menu.
2) Mountain lions. These are probably the most significant animal threat in my state. After all, their diet normally consists of an animal that weighs as much as a human, that has better senses, and is much faster. We must look like slow and dumb deer by comparison. Add to that the fact that mountain lions are extremely effective predators, and tend to ambush their prey, and you've got a fearsome adversary (should it look for a fight). They're generally elusive though, and will often back down from little more than aggressive posturing. They're also no bigger than a person, and are considered thin-skinned. If your gun will stop a person, it'll stop a mountain lion. Still, I wouldn't want to go hand-to-claw with one of these cats.
3) People. Their threat is the easiest to understand, and the hardest to predict.
4) Moose. These darn things get mean during the rut. I've been charged by a moose before, and it looks like a deranged freight train. Just get out of their way.
Anyway, I see personal protection as a different category than "bumming around in the woods". For bumming around I usually carry my cheap old bolt action .22lr. It's a great lightweight plinker, and works well for small game hunting.