GG's Bad Habits is one of my favorite songs by him...insane lyrics
Feederz - Jesus is another cool and politically incorrect song
Queers - Fagtown
Angry Samoans, as already mentioned - they have a lot of offensive songs. Easily one of the best punk bands because of it (my opinion of course).
Eater has that song Get Raped...not very pc.
Dictators got several
Vomit Pigs - Useless Eater
Fang - Destroy the Handicap
Nobunny - I am A girlfriend
Most FEAR songs
Wire - Mary Is A Dyke
Some by band name alone: Hitler SS, Nazis From Mars, Child Molesters, Black Randy, Joy Divison, Martin and the Brown Shirts
Then there are all the bands with Nazi facinations: Dead Boys, Stooges, Ramones, .... I think Skrewdriver kinda got into it too?