Built a little addition to my collection

My friend works for an architecture firm, and one of his clients used to own a baseball card store. As appreciation for some of the work my friend did for him, he gave him some baseball cards. My friend doesn't have any interest in baseball or cards, so he passed them along to me. What he got was a packs worth of each of five sets (guess he had them laying around?):

1993 Leaf

1991 O-Pee-Chee

1993 O-Pee-Chee

1992 Stadium Club Series I (which is cool because I have most of II and all of III)

1991 Studio