Um, my collection of Castlevania stuff, I guess? Definitely not the biggest collection out there, but I have a good amount of decent stuff, imo. I just got a glass display case that my wife painted, and it houses my favorite stuff from the series. I may upload some photos if anyone is interested in seeing it.
As far as gaming accomplishments, I am competent enough to beat the CV games, but not great at them or anything. So maybe my best accomplishment is beating US CVIII using the Alucard path, or something. I don't know. I'm a lot better at the Contra games than I am the CV games, but I've always liked the CV series a lot more.