I would like to someday own every release of Shenmue and Shenmue 2, which I have most of them, but it would be nice to own the others as well.
It isn't for a series specifically, but I've also been going for a complete Namco Guncon big box collection for a while. I currently have every North American Guncon and Guncon 2 big box except Point Blank 3, which I ironically owned as a kid, but no more sadly. I would also like to get the PS3 Guncon big boxes of which I think Time Crisis 4 is the only one.