I have only recently gotten my collecting focus somewhat stabilized. I began as just a card collector that would buy a T205 Matty and a 2011 Topps pack on the same day. While I still venture outside of these things occasionally (like opening vintage packs and buying cheap modern rookie cards), these are my main focuses:
1.
All things Harmon Killebrew. I have his Topps Basic set and am working on his Master Set. Also lots of photos and other items. My favorite piece is this 1960 Topps Flexichrome original featuring Harmon & Rocky Colavito for a card that was never made (thanks Bob Lemke!):
2.
Vintage photos. This is more recent but I really love these. I recently got my first Charles Conlon from a Net54 member and I doubt it'll be my last. I still think this is my favorite, and one of the first that I bought. Branch Rickey:
3.
1951 Bowman. I haven't made much progress on this set in awhile, I need to get back into it. Over halfway done. My only rule is to NOT use ebay at all to help complete it.
I have a lot of other pieces that don't really fit in but hey, it's all fun!