1. Manny Pacquiao | This content is protected comes in hard and fast (that's what she said) and fighters' entire training camps are predicated on how to avoid it 2. Naoya Inoue | This content is protected Frightening in both hands with any punch that he throws 3. Gennadiy Golovkin | This content is protected Heavy, thudding; wreaked Canelo in 2 fights 4. Guillermo Rigondeaux | This content is protected Thing of poetic violent beauty; takes balls, confidence, speed, and precision to throw it 5. Vasiliy Lomachenko | This content is protected Active, probing, rangefinding, defense, offense
For me #1 is Gennady "GGG" Golovkin's Cranial Crusher overhand left hook. Danny "Gift" Garcia's long left hook is a beauty too. Honerable mention for Martinez Aguilar's fashionably late to the party left hook bodyshot.
But that thing has only KO'd Khan's paper chin and an ancient and bloated Morales... Hasn't been shown to be particularly devastating otherwise.