Besides the obvious "fire in a crowded theatre" there a raft of things you may not say:
• you are not permitted to reveal to people material classified in certain ways
• you are not permitted to broadcast copyrighted material
• you may not make death threats against people even if you can prove that you are not a threat to them
• you may not reveal information about certain companies if you are in certain positions
These are speech of 'any' sort and I'm comfortable with the penalties (sometimes criminal) for them. I don't think they're dangerously close to criminalising certain ideas and thoughts. In almost every case you're free to think what you want and imagine what you want.
Any opposition to laws that attempt to abridge hate speech cannot derive from a general opposition to abridging freedom of speech unless one also objects to the restrictions I mentioned earlier.
> classified material - potential threat against life
> copyrighted material - protected by the constitution elsewhere
> death threats - direct threat against life (ability is irrelevant)
> corporate espionage - generally falls under contract law
Any and all of these may be abused regularly, that doesn't mean that any of them are protected under free speech.
You have rights; you are responsible for the consequences of exercising them.
This was the justification for banning so-called trolls from twitter.