Nothing beats a rifle in bear country (12 gauge with 00 buck or slugs as my second choice) but for pistols I would say .357 mag.
Went salmon fishing in Alaska once...
I'm paraphrasing from the back of the Alaska State Fishing License:
"It is recommended, when fishing in bear country, to carry a .308 or more powerful rifle at all times, as the bears may contest YOUR right to THEIR fish."
We had a Remington .308 pump (my low-land deer gun), loaded up w/ 185gr soft-nose ammo.
I'd only use a pistol on a brown bear if it was that, or death...
After considering briefly, Frank decided to accede to the latter alternative. Even though he felt sore for two weeks, Frank soon recovered and vowed revenge.
He headed out on another trip where he found the black bear and shot it. Right after, there was another tap on his shoulder. This time a huge grizzly bear stood right next to him. The grizzly said, "That was a big mistake, Frank. That was my cousin and you've got two choices. Either I maul you to death or we have rough sex." Again, Frank thought it was better to cooperate.
Although he survived, it took several months before Frank finally recovered. Outraged, he headed back to the woods, managed to track down the grizzly and shot it. He felt sweet revenge, but, then, there was a tap on his shoulder. He turned around to find a giant polar bear standing there. The polar bear looked at him very sadly and said, "Admit it Frank, you don't come here for the hunting, do you?"
Speaking of jokes and bears....
If one is going to spend time in bear country, one should tie small bells on your shoelaces, so that a bear can hear you coming and therefore won't be surprised. You should also carry pepper spray, if you should be so unfortunate to come in close contact with a bear.
You should also learn the signs of recent bear activity. The presence of feces can tell you if there are bears nearby. You should also learn how to tell what kind of bears there might be nearby. Black bear feces is smaller and has little bits of leaves and berries in it. Grizzly bear feces has little bells in it, and smells like pepper.....
Not serious... http://s62.photobucket.com/albums/h1...t=DSCF1592.flv
Very serious... http://www.youtube.com/watch?v=OvooqbW9dz4
For a first auto, I'd get a 9mm. Ammo relatively cheap, low recoil and good SD ammo available. As far as black bears go, I worked in the woods including Washington and Oregon for better part of 40 years and never had a problem with them or worried about them. If they hear you first, you'll probably never even see them. Wierd humans caused me much more problems in the woods than wierd bears. If a cougar decides to attack you, odds are you will be attacked before you even know he is around(rare). 9mm with right ammo will handle cougar if you see him first.