I'm of the opinion that any joke that perpetuates the marginalisation of a group of people based on their gender or race is a pretty harmful one, intentionally or otherwise.

Humour is a part of society; what makes something funny is its topicality or revelance, which is usually dependent upon a shared cultural understanding between joke-teller and audience. But humour also shapes society, contributes to society.

Any joke that contributes to the casualisation of racism or misogyny is as offensive as the atrocious grammar with which it's commonly written.

No racist jokes, please; no misogynistic jokes, please...

And anything which is worth controversy is probably better said seriously than in jest.