This penny card only brings me up to 22 unique base cards from 1993 Fleer Ultra, but I've got most of the Cardinals and A's due to a group break a few years ago.
1993 Fleer Ultra #216 Steve Shifflett
Steve Shifflett only played in 1992, yet made it into most major releases of 1993. I figured that was because of the larger sets back then, but Fleer Ultra only had 650 that year. He finished 15 games, but recorded no saves, which has to be some kind of record.