I have quite limited experience compared to the rest of you, having only fired about 12-16 guns. However, of those I have shot, in long arms I love my grandfather's Remington 870. It's the definition of an old school shotgun, weathered and short-barreled, but I'd have that thing by my side before any other weapon if my house was being breached.
In pistols, I love my Beretta PX4 Storm. I know it's a polymer gun, which probably alienates it to a lot of steel-frame purists, but I just love the darn thing. I have fired significant quantities out of my brother's Glock 22, my father's Colt Cobra .38 and Colt Python .357 as well as his Beretta 96FS. However, the action of the PX4 tames the .40 considerably, and when push comes to shove it's the handgun that most fits ME, the one that my hand molds to and my body and mind are instantly confident with the second it's in-hand. In addition, it's one of the few guns I've fired - the Glock and Colts fall under this too - that has never misfed a round, ever. I would trust it with my life in a heartbeat.