Canizales the younger is the poster boy for this imo. At his sadly rarely seen best combining physical talent and skill (and from an aesthetic standpoint) he makes the likes of Inoue, Donaire, Rigo look basic in comparison. The definition though of an unambitious underachiever with a lamentable CV. R Lopez, Gushiken and Galaxy. Tito in his mid-welter days, 95 to 98ish.
Tony Tucker is a good shout. He looks excellent on tape. Well, at least in the fights I saw him in. I'll mention Robert Garcia - whom most people know for his success as a coach. When I was watching him fight - his skillset and technique looked to me to be on par with the likes of Morales, Barrera and Marquez. He just did not have the same mental fortitude and physicality as those 3.
His career's not over so maybe he'll have a crazy turn-around and start fighting the best (though I highly doubt it) but Tank Davis does look tremendously talented on film. He's fast, he hits hard, and he's got a good ring IQ. His resume isn't much to talk about but he passes the eye-test very well and clearly has a more than solid understanding of the science of boxing.