Well, you are going to get more different answers to this question than there are probably members on this board. [:0]
Personally, I am not a big Glock fan. There are some handguns that fit in my hand very naturally and none of the Glocks seem to be it.
I've heard nothing but good things about SIGs. I've handled a few, but again, not natural for me.
Now, as a military fan of the .45, I'd recommend that. Now as to a model, I'd be pointing you in the direction of a Kimber. This is the handgun that every factory, non-gold cup, Colt .45 wants to be.
I own a Delta Elite 10mm (basically a 40 cal), am impressed with the cartridge, but would still rather have a .45 if those were my choices.
Finally, my personal choice for a handgun....Browning Hi-power Practical.
I was drawn into the Beretta court in the 80's, and was impressed. I bought the Delta Elite on a whim, and have been less than enthused. Finally, I purchased a Hi-power on a whim and have never looked back.
With the variety of 9mm cartridges out there, there is something that is sure to please. But as far as the Hi-Power goes, this is the [b]most[/b] comfortable and [b]most[/b] natural pointer that I have in my safe.
'nuff said.
Regards....