No matter what the question, if its about a revolver the answer is Ruger.
.357 mag is a good all-around caliber if you're only going to have one. You should always be able to find ammo for it and it gives you the option to shoot cheaper, lighter recoiling .38 special ammo as well.
Do you want double or single action?
Get a 6-6.5" barrel for better accuracy and velocity than the snub-noses but still short enough to carry.
Just my .02 for what it's worth
"Peace is that brief glorious moment in history when everybody stands around reloading"