It's entirely possible you've not heard of this 1988 film, even though the director is Oliver Stone.
I stumbled across it in the TV listings one day and recorded it. Then I watched it over and over and over. It's the story of a (Jewish) radio talk show host in the Dallas area whose show is on the verge of 'going national', and who seems to have his show dominated by phone calls from people who don't like him. He, of course, plays up to this, invoking stereotypes, racism, shame, whatever he can think of to get a reaction. He receives death threats in the mail, over the phone and the film ends with him being shot and killed outside the radio station after his show finishes. If it sounds mildly familiar, the story roughly matches that of one Alan Berg, a Denver-based talk show host killed by white supremacists, although the central character himself is based more on LA-based host Tom Leykis.
The script is by Eric Bogosian, who is also the star and who also wrote the predecessor to the film, which was a stageplay by the same name. Bogosian is utterly convincing throughout as a man playing up to whatever he has to - even with his character occasionally breaking out of 'on air' persona (for instance, when he realises a caller claiming to be a rapist really IS a rapist being sought by the police) - and the supporting cast, including John C. McGinley (from Platoon or, for more recent generations, Dr Cox from Scrubs) give the whole thing a tremendous sense of weight and atmosphere. The final monologue at the end of the last show is compelling - the camera circling the room, centred on Bogosian (or is it that he and the camera are still and the room is spinning?), the tense on-air silence ("dead air, Barry, this is DEAD AIR") and payoff line "I guess we're stuck with each other".
If you ever saw the TV show 'Midnight Caller' from the same period and wondering if it's like that, just imagine Midnight Caller with a less-likable host, some crazy callers, severe attitude AND a much more accurate technical layout for a radio studio (seriously, that portable headset Gary Cole used in Midnight Caller was NOT broadcast quality). It's a GOOD version of midnight caller.
And over the closing credits, while 'Telephone and Rubber Band' plays, we hear a montage of callers discussing the killing, and you realise the depths and shallows that the film just took you through - all the way from that fact some people liked listening to him and miss him, through questions of who did it, right through to freedom of speech discussions and the value of giving neo-nazi groups access to the airwaves, and you realise just how much ground was covered in this film.
And then you watch it again.