Hi David. If the only interests you have is baseball, then you have no need for non-sports cards. If you have any interests outside of baseball, then there is probably at least one (if not multiple) non-sports card set that covers that interest.
For various reasons, some of my favorite non-sports sets are the N2 American Indian Chiefs, the T77 Indian Life in the '60s (who doesn't enjoy a good bowl of Puppy Stew), the 1934 National Chicle Sky Birds (nothing screams Art Deco and the early fly days like this set), G-Men and Heroes of the Law, Laugh-In, and of course, Wacky Packages. Once you start poking around
www.non-sport.com, I'm sure there's something you'll find that will drag you into the abyss.