Does it go bang? Does it go bang... pretty much no matter the conditions? Do bullets come out the end, and hit what they're pointed at, pretty much every time?
If so, then it gets the Four Nine Foxtrot Stamp of Approval. I'd be proud to carry any of the fine examples of modern personal armament listed in this thread into combat. Especially several at the same time, and particularly if I didn't have to pay for them.
I like my Sig P226. It fits my hand like it was made for it. We understand each other, my Sig and I. Oh, she nags me a little. "You don't take me out as much as you used to", "Have you been shooting another gun?", "Lately, when you've cleaned me, it hasn't felt as intimate. Do you still love me?" She keeps pestering me to get a CCW, to take our relationship to the "next level", whatever that means. I keep explaining that there's nothing I would like better than to make our relationship right in the eyes of God, instead of living in sin as we do, unable to associate in public... hiding our relationship from the world... but that it just isn't allowed where we live.
Other than that, though, we get along fine.