I tell folks, only half kiddingly, that my wife and I collect animals. We have a small hobby farm and have cats, dogs, and horses. Following from that, I collect horse themed pre-war tobacco cards. Mostly early 20th century British issues, but I have also completed all three Kinney Brothers sets (N229 to N231)
I started on the Allen & Ginter World's Racers (N32) but haven't really done much with it in several years, although I do have the album premium
I also help my wife with her mid-century glass collection. She started with barware and has expanded into swung vases, ashtrays, and more recently marbles. Sometimes I feel like I am enabling a hoarder since her collection is starting to consume every flat surface in our small house. But, it makes her happy and she is actively packing away the less interesting items.