9mm - 5903: It has an alloy frame and is much better balanced than the 5906.

.40 - 4013: It's light, flat (single stack) and just plain nifty. I have a 4006, but I vote for the 4013.

.45 - 4566: I think its size beats out the 4506.

10mm - 1066: Hands down, the best 10mm S&W. But I like all three of my 10mm pistols (1066, 1076 & 1006)

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1st Signal Brigade, RVN '70