Two recommendations: a Bul M5 or a Tanfoglio.
I used to write gun reviews for a periodical on a regular basis. A friend in the business asked me to review a Bul M5. I did and it was the finest double-stack .45 I ever shot. It still retains that status. It is now imported by Charles Daly. I'm not sure if it is the same as the one I reviewed a decade ago, but it's made in the same place by the same company.
I was frustrated when I reviewed that pistol because I HAD to send it back. Usually when you review a gun they let you buy it at a discount or give it to you. They wouldn't even let me buy it at full retail. They wife recently gave me her permission to buy an M5 and I am currently shopping. Guess she just couldn't stand seeing me bring up pictures of M5s on the net and sighing anymore.
Plus, Charles Daly has a true lifetime guarantee. And the boss at Charles Daly is a regular here on THR. So if you ever have a problem with a Bul M5...
The Tanfoglio is a whole 'nother thing. It is a CZ clone, but takes the CZ format to the next level. Get a Tanfoglio steel-frame, full-size .45 and you can get conversion kits to make it shoot: .41 A&E; 10mm auto; 40 S&W; 9mm; .38 super; 22 rimfire - and with very little effort .40 Corbon; .357 Sig and 9X23. One frame, many calibers.
My Tanfoglio (better known as EAA Witness) in full-size, steel frame will rip a single big hole at 25 yards, but it can be 10mm auto in about 15 seconds if I want.
EAA's service sucks, but there are a lot of suppliers of parts and accessories. And, if you do like I do (get a full size steel frame, a full-size poly frame and compact poly frame) worst case scenario is one becomes a parts gun to keep two other guns in the caliber of your choice operational.
If I were to trust my life and that of those who depend on me on one gun it would probably be the Bul M5, but if I had to depend on one gun to get me by when the SHTF it would certainly be the Tanfoglio - with a whole lot of conversion kits, frames and different kinds of ammo...