Well mine is pretty diverse. I took the time to make a list of all the manufacturers/brands that are represented in my collection. I have more than I realized. There are single and double action revolvers, DA/SA pistols, SAO pistols, break open rifles, shotguns and handguns, bolt action rifles, lever action rifles and shotguns, semi auto rifles and shotguns, pump action rifles and shotguns, bolt action rifles, and a derringer. Stainless, Blue, ceracoat, nitride, plastic, fiberglass, carbon fiber ,wood, camo, anodized, polished, matte, other random finishes and treatments. I dont have any nickel though.
Baikal
Barrett
Beretta
Black Aces
Bond Arms
Browning
Colt
Christensen Arms
Dan Wesson
EAA/ Tanfoglio
FNH
G force
Glock
H&R
Henry
Kimber
Magnum Research
Mec tech
Molot
Mosin Nagant?
Mossberg
Palmetto State Armory
Para USA
Pedersoli/Navy Arms
Quentin Defence
Remington
Ruger
Savage
Sig Sauer
Smith and Wesson
Springfield
Thompson Center
Weatherby
Winchester
I think thats it...there's some noticable gaps that need filled now that I look at it. H&K, CZ and Taurus to name a few though I have had an H&K and a few Tauri come and go over the years.