I can't say I'm a fan of his but one of the anthologies he edited, Again Dangerous Visions, had quite an impact on my view of the world. He didn't write any of the stories, but he challenged the writers to go beyond all boundaries ... and boy they sure did. Ellison doesn't do happy endings and given his frustration with the world around him, I'm not surprised.
He sees writing as a job just like any other. Once he was given a sealed envelope which he opened at a bookstore one morning. His typewriter was set up in the display window and his challenge was to write a story based on the few words Tom Brokaw had written inside that envelope. Five hours later, the story was finished while people watched. I don't know how good the story was but Ellison is a perfectionist so my guess is it satisfied him or he wouldn't have stopped.
He has written screenplays for Outer Limits, Star Trek and was a consultant on Babylon 5 (which I though was a brilliant show). He's had a long association with Hollywood although it hasn't been pleasurable for him. No one seems able to translate his vision of his stories to the screen to his satisfaction. No surprise. Those of us who love to read are seldom pleased with the results when a book is made into a movie.
I thoroughly enjoyed this documentary about Harlan Ellison. He's brilliant and irritating, funny (although he may not always intend to be), a really fiesty bantam rooster. I strongly urge everyone to buy the DVD, he's worth watching more than once.