Best stock out of the box, it's a tie, the Beretta 92FS, and a friend's super expensive CZ clone, not a Sphinx, more expensive. Solid SS, really nice wood grips, made in Canada, I think. Awesome gun. I've never seen a gun that smooth before or since. It cost something like $3000, used.
Customized, I would have to say the CZ-75 my friend bought off Gunbroker in the very early days that the site was in operation. He's still kicking himself for selling it, even at a huge profit.