Thanks for all the replies guys.
Just to clarify, I'm not necessarily suggesting a home defense situation... just if you were asked to choose the one gun right now that you know would fire 5 times reliably... which would it be?
To answer some of the questions, I trust that all of my guns will fire when the trigger is pulled.
My Savage 110 bolt action will occasionally jam if the bolt is cycled at a certain speed. One FTF entirely due to ammo. It's 100% a range gun, and I normally feed it one by one, so it's not a big deal.
Once or twice, the 870 extracted a shell, ejector kicked it, and the shell ended up sticking out of the ejection port perpendicular to the barrel. Sure it's just a fluke, but it's possible.
WASR-10 jammed because of the mags. I bought it, and essentially took it straight to the range. One of the mags looked like it had been dropped on the feed lips. It jammed. I was fairly sure it would. I only have 60 rounds through it, and I know I'll work it out till it goes bang every time.
But right now, the gun that I know will work is the Beretta.
I don't have to hold it a certain angle, cycle it the way it likes, feed it certain ammo, or do anything else. It just works.