22lr (of course)
12ga (any)
AR15 and/or AK47
M1a/M14 and/or M1 Garand.
I have had all of these at some point but in my effort to catch all the Pokemon's I have had to let some go. I dont necessarily agree that everyone should have all the above since I dont but I would say everyone should have:
M1 Garand.
1911 Preferably USGI but they are all cool.
A lever action rifle.
A Colt or copy of the iconic Single Action Army.