Well... anything by GG Allin. This video is very tame, compared to what normally goes on at one of his shows.
Sex Pistol's Bodies
To be honest though to get the Guardian bitching about a band or music genre you don't even need to sing about rapists or spastics. All you need to do is form a band that doesn't for whatever reason have any ethnic minorities in it. No kidding, they ran a story a few months ago claiming the subtle racism of British indie rock.
I think just about anything comes out of Mark's mouth is un PC, it's Guttermouth's main draw.
GG Allin was such...an awesome creep.
How about "Under My Thumb" by the Rolling Stones? The singer is bragging about his girlfriend's submissiveness, and the line that really gets me is when he sings, "I can still look at someone else." Yeah, I know it's a mild example, but it's the one that stands out in my mind.
Oh, wait, I just thought of a far more horrible example..."Little Bit of Whore" by Johnny Thunders when he briefly worked with Wayne Kramer. It's a great rock'n'roll song, but the lyrics can NEVER be heard in mixed company.
Anything by The Macc Lads, especially the re-write of Bandaids feed the world!
and The Misfits Last Caress of course!
This Jabbers song fits the bill as well as this Angry Samoans tune that by today's standards are certainly offensive!
Ona recent episode of The Big Enchilada, I played "Davy, You Upset My Home" by Joe Tex. It's about a guy who's jealous because his girl is really into Davy Crockett. (I think this is from the late '50s when Davy Crockett was a very popular TV show.)
The girl even buys Davy Crockett false teeth because, Joe sings, "I punched her in the mouth last night."
Another line: "I whipped her so until she went insane. And now she wants to buy herself a Davy Crockett brain."