Well..."Collector" sounds so much better than say, "obsessive accumulator of firearms"!
My focus tends toward military issue weapons (handguns and rifles) of the US and Germany. Insofar as Germany is concerned, my focus is WW1 and WW2. Insofar as the US is concerned, my focus has been WW1 through the Desert Storm era.
In some cases, (Lugers, High Powers, 1911/1911a1's), I have multiple examples.
Fortunately, also (convenient excuse for the wife unit), they make for good investments!
It's probably just as well that I can't afford NFA toys, as I'd love to have an MP40, Thompson, .30 cal Browning, MG 34 & MG 42, etc., etc.!