Buying a gun is like buying a pair of shoes. What fits well for somebody else, may not be a good fit for you. The only way you will know if a gun is for you is by shooting it.
When it comes to shotguns, I have always heard good things about the Mossberg 500, and the Remington 870. Many law enforcement officers trust their lives to these weapons. They are both time tested and battle proven.
I have the 870 marine magnum, and I have been nothing but pleased with it. Listen to what the gun store has to say, do some research on your own, ask some more questions, and see if you can shoot it before you buy it.