In the modern era who does? Thoughts? It's the best punch out there, no? Certainly the most devastating - ask Juan Diaz.
The uppercut is the best punch to finish off an opponent when he is weakening yes.... JMM has probably the best one currently, taking into account the power behind it and timing - not timing the punch correctly.... I mean choosing the right time to actually use the punch.
It's deadly just because the neck works as a shorter hindge in the up and down motion, so it is harder to distribute that energy, when compared, say, to a left hook, where the head and neck have more give to soak the punch up. Also, it's sneaky, nobody has eyes in their throats. On this planet.
Tyson springs in mind too. Not only because he finished a lot of his opponents off spectacularly with an uppercut, but because on Tysons worst day against an opponent on his best day who was fighting a perfect fight (Buster) and so was destined to win the match, Tyson was still able to drop his opponent with an uppercut from hell.
Mayweather when he uses it and Kesslers, best short uppercut technique out there, short ,compact, puts the hips into it perfectly and its fast as ****