not even a choice. Beretta Para 9, the other options are not even close. I am also a fan of the taurus 24/7 but I would not buy anything smaller than the 40. IMO thats the best it gets from taurus I actually shoot a millennium pro (PT145 w/ pic rail) in the 45acp.
With all due respect, this is NOT a good response to the OP - I understand John likes his Baretta but to put this pistol ( or most modern, quality 9s for that matter ) leaps and bounds ahead of the others is foolish. Glock, HK, CZ, S & W, Ruger, Springfield (XD), Walther, etc etc etc (and I'm leaving out a bunch of others) , ALL make quality firearms. Will someone on occasion get a dud from any of the companies? - sure, and those are the stories that makes the intranets so interesting. Don't fool yourself - unless you are just surfing for the lowest price on a pistol get what YOU like and shoot one if you can for yourself. When shopping for and piece of gear that you will theorhetically rely on to save your life, why skimp? The difference between pot metal crap and a quality piece is a few hundred bucks (and BTW the 2 samples of "saturday night special" quality pistols - a raven .380 and a jennings pistol, they ran like typewriters when I had the chance to shoot them).
Caliber: a 9 will serve you well provided you load it with a quality cartridge. Cor-Bon, Hornady, Federal, Winchester are some companies that sell quality hollow point ammo whose performace will come close to larger diameter calibers. As always, shot placement is KING. Again, IMHO, ammo technology has evolved to the point that most of the major manufacturers offer quality hollow point ammo that expands reliably and produces the "desired effect". Pick a quality 124 grain load from these manufacturers and personally, I would feel well-defended.
My personal pick? Like alot of others who have responded, I like the glock 19 - the perfect 9 in the opinion of alot of gun guys aside from myself.. Almost in the "compact" category, 15 round capacity, cheap(er) magazines and as reliable as any of the 6 other nines I own - including a Ruger SP-101 revolver in 9mm. Just a sweet, sweet gun and it holds twice the ammo that a standard 1911 does. Biggest complaint by others is the grip angle - doesn't bother me a bit and it hits where I point it...good luck and if you get it down to 2 pistols and can't decide - GET BOTH!