Each firearms maker signature firearm.

Benelli: M4

 

Smith & Wesson released their poly-frame Bodyguard .38 shortly after the poly-frame Ruger LCR.

 

HK has a number of iconic guns; the G3, the P7, the USP and the Mk23 all come to mind. But I think the MP5 is their most iconic guns, perhaps one of the most famous guns of the modern era.

 

I'll add the Barrett 82A1.

 

The Thompson 1928A1 "Tommy Gun."

 

Okay, just one more: the Chiappa Rhino.

 

IMI / Magnum Research Desert Eagle .50 AE.

Deutsche Waffen und Munitionsfabriken (DWM) 9mm Luger pistol

Mauser K98

 

I think for Ruger I'd go with the 1955 flattop Blackhawk .357 Magnum

 

Savage 99

 

As far as big game & varmint hunting the only rifle that gave Winchester & Marlin competition as far as lever action's were concerned was the Savage model 93 & 99 with the ability to us the spritzer type bullet pushed with more powder for longer range type hunting?

 

Sig - P220 (though I'd say p228 as well)
Browning - Hi Power
Izhmash (now Kalashnikov Concern) - AK47/AK74 (their runner-up icon would be the Makarov PM pistol)

Also, is this just open to currently operating concerns?

Radom - Viz wz 38
DWM - Luger p.08

 

Colt-Single Action Army
S&W-Model 10
Ruger-Blackhawk
Browning-Hi-Power
CZ-CZ75
Beretta-Model 92
Winchester-Model 94
Remington-Model 870
Ithaca-Model 37
SIG-P210

 

Ruger single six
Blackhawk

Marlin Model 39

 

AMT
Volquartsen
Tactical Solutions
Nodak/Spud
Magnum Research
KIDD
MOA
Just to name a few.

Who did Ruger copy for the Standard Auto? The .44 carbine? The Blackhawk? The Single Six? The 10/22? Anything but the LCP???

 

I was thinking along the same lines, particularly since the OP did not mention H&K in the first post. But many of these, though innovative and iconic didn't lead to much in the way of copying.
MP5 (all flavors) with the delayed roller lock innovation which really separates it from any SMG and semi-auto PCC's out there, but was never duplicated (though it was cloned)
P8 is a very early striker fired gun that led to the Glock but the squeeze cocker and delayed blowback piston tube didn't get copied until Walther did it recently
The USP might have been the first polymer full size semi-auto high capacity battle-class sidearm. Indestructible, passes any durability test thrown at it, and also excellent longevity. The Compact version might be usable and I prefer it with the light LEM but it is an excellent gun with few copies.
The MK23 well, clearly no copies.
B

 

Colt -SAA(I wouldnt count the 1911 just do to the fact that its was JMBs brain child .)
Smith and Wesson- model 10,model 19, and model 29
Ruger-10/22,super blackhawk
marlin-model 60, 336
remington-870,700
mossberg-500/590
winchester-1873,model 70
ithaca-37
springfeild -M1a
glock-17,22

 

To use the OP's list though in a different context.

Were a fella to say:

"He had a (insert manufacturer here without model designation) that day"

And I were to infer through my experience. The first firearm that I would likely mentally jump to would be;

Cz - VZ75
Ruger - 10/22
Remington - 870
Colt - 1911
S&W - Model 10 or maybe a 15
Walther - PP/K
FN - FAL
Sig - 230
Beretta - M-9/92
Glock - 17
Springfield Armory - Garand

 

I like your standard, but based on that would revise...

Remington - 870 or 700 depending on the crowd you're around
Colt - SAA (I usually hear "1911" for the autoloader since most people seem to have a non-Colt made version)
Springfield Armory - 1903-A3 (everyone I know referrs to a Garand as a "Garand" or an "M1" regardless of maker)

 

Sorry, I know it was a typo, but "spritzer" type bullets cracked me up. I had a vision of a bullet fired with wine and soda.

When I think of Kel-Tec, I think of the Sub2000. Not because it has been copied, but because they seem to be the only ones I can think of making something like that.

 

Walther P38 thru to the P5.

 

Remember some of the fore mentioned guns are not that old in terms of design so they are protected by copyright laws. 1911 and such are no longer which is the reason why everyone makes them. Once a company like Sig losses their copyrights on their p series guns other will undoubtedly copy them.