When I think "combat" handgun, I think military. So, I wouldn't throw out the .40S&W (even for police or individual use I wouldn't). For a major institutional buyer the costs aren't much different between the calibers. For you and me buying quality JHPs the costs aren't much different either. As for the snappy part, I used to agree but in most modern platforms it isn't that snappy (shoot a K-frame or L-frame .357mag back to back with the .40S&W and see what you think of it then, the .40 will seem like a .22, and few people think a service sized revolver in .357mag is unmanagable).
Anyway, I'm going to steer clear of caliber now and just go for guns:
-SIG. SIGs are among the top combat guns today and will be for some time.
-Glock. I hate Glocks, but they are reliable and simple to use and maintain.
-S&W M&P. 'Nuff said. I really think the U.S. military should throw the next contract this way. They are well made, reliable, and made in the USA.
-FNP
-Beretta 92/96 and the Taurus version (PT92 and PT100)
-Browning HP
-Colt (or any major manufacturers) 1911
-CZ 75B may be up there.
I'm sure I'm leaving out a ton of great guns. That is the real point I guess. It is hard to say which is the best (and best for what- accuracy, ease of maintainance, reliability, the best overall combination, best combination for the price, etc.). There are a ton out there that are good solid combat handguns that will do the job and take the abuse of combat, that are relatively easy to maintain. The military will have a ton of tests to wean out some and pick one that works for what they want. Pick the one that works best for your particular criteria.