Hamachi

It is so popular that Hamachi is now a English word.  Almost all Hamachi in the US is farm raised.  Quality of farmed Hamachi has been vastly improved because of advancement of farming techniques.  It is so much so price of farmed Hamachi is sometimes higher than wild one in Japan.

Kampachi is not as fatty as Hamachi but its meat is firmer.  Many fish aficionado actually prefer Kampachi.

Hiramasa is a high-end product typically found only in super elite restaurants. Hiramasa lives in warmer water than Hamachi.  As such, it is not as fatty.  Hiramasa is not farmed in Japan.