colt 1991a1
colt ar15 pre-ban (for the $ value)
and the worst sale i made was
manurhin walther pp 32acp that i bought while stationed in germany and brought home with me
I've sold several other firearms, but most of them were not to my liking for some reason and there were no regrets parting with them, but the three above I do miss, and it would cost much more to replace them now than it did to buy them back when I did.