Although I do not collect the set, and don't know much about it (other than information gleaned from online sources and threads on this forum), I'd toss out T216 as an interesting, esoteric set to collect.
It's a regional set sharing the attractive poses and colors from the American Caramel sets. Not only does the set offer a few different backs, the thickness of the card stock and glossiness of the front will vary based on the factory of origin. Add to this the fact that the cards are fairly scarce, and are typically found in lower grade condition, and you have a set that is not only interesting, but indeed esoteric!
Here's a couple threads that discuss the set, along with many cool cards posted by members....
http://www.net54baseball.com/showthr...highlight=t216
http://www.net54baseball.com/showthr...highlight=t216