I target MLB related cards only, but have absorbed others in buying a few collectors out.
I Personally Collect Alex Bregman, Yordan Alvarez, Luis Robert and Aaron Judge cards.
I have started trying to assemble some sets that seem to be more readily available, like "TOPPS - Stars of MLB" and others that are not as readily available as SMLB, it seems, like "Select '96 - Team Nucleus". I am also trying to collect the various "Gallery of Stars" sets from Panini/Diamond Kings. But in truth, I have just been collecting everything I can get my hands on. I have, however, noticed that my interests are changing.