As others have pointed out, this is a personal decision. There are good things and bad to say about either type.
I like revolvers because they're simple. You pull the trigger and the gun fires. If for some reason it doesn't fire (very rare with revolvers from what I have read), you pull the trigger again. They're easy to clean. They're not damaged by being left loaded for extended periods of time. Yes, you have fewer rounds than in a semi-auto, but realistically, if I'm in a situation where I need more than five or six rounds, I'm probably screwed anyway.
There's one more reason I like revolvers. If your attacker is close, like on top of you, and your weapon is pressed against the attacker's body, you can still fire a revolver. A semi-auto is likely to jam because the slide can't move freely. At least, that is what I've been told.