Gene Hackman is imo grossly underrated but at the same time well known as one of our greatest and most beloved actors. He's up there with Denzel, Pacino, De Niro, Brando, Samuel L, Eastwood etc. The character of Popeye Doyle is iconic because of him and his skill of bringing such depth and charm to such a hard ass, bigoted smart ass like Doyle. You still root for the guy even at his most blunt and crazy lol.