Big Name Fan: David Letterman. Zevon was often guest bandleader and has performed on Letterman's show more than any other artist. Letterman is a great fan of Zevon's and provided backing vocals on "Hit Somebody! (The Hockey Song)"
Also: Mitch Albom, Peter Asher, Dave Barry, Jackson Browne, Lindsey Buckingham, T-Bone Burnett, David Crosby, Don Everly, Phil Everly, Don Henley, Carl Hiaasen, Jon Kellerman, Stephen King, Jon Landau, Richard Lewis, Bonnie Raitt, Paul Shaffer, Bruce Springsteen, Hunter S. Thompson, Billy Bob Thornton, Jesse Ventura, and Dwight Yoakam. (Going by the list of his friends who contributed to a book about his life.)
If you also include people who've worked with him numerous times or have covered his work, you can add: Bob Dylan, Adam Sandler, Steve Earle, Linda Ronstadt, Wallflowers, Pete Yorn, Ry Cooder, Pixies, Jill Sobule, R.E.M., Jennifer Warnes, Tom Petty, Neil Young, Dwight Yoakam, Jim Keltner, Jeff Pocaro, Waddy Wachtel... Let's just say that he's incredibly popular within the business.
Covered Up: Zevon covered Bob Dylan, Steve Winwood, Ernie K-Doe and (with his side project the Hindu Love Gods) Prince's "Raspberry Beret".
Linda Ronstadt had a hit with Zevon's "Poor Poor Pitiful Me".
The title track of her album Hasten Down the Wind is a Zevon cover.
As did Stevie Nicks with "Reconsider Me".
Dylan later repaid the favour by putting a whole bunch of Zevon songs on his regular set list.
The Grateful Dead frequently played "Werewolves of London" in concert between the late 70's and the early 90's.
After his death, a bunch of artists made a tribute album titled "Enjoy Every Sandwich," after a quote from his last appearance on Letterman. It includes covers by Bruce Springsteen, Bob Dylan, Pete Yorn, The Wallflowers, his son Jordan Zevon, and a suprisingly good cover of "Werewolves of London" by Adam Sandler.
Crosses the Line Twice: "Excitable Boy". The title character rapes and kills his prom date, drives her corpse home afterward, is committed for 10 years, then digs up her grave when he's let out.
You forgot to mention the part about building a cage with her bones. Perhaps that's a third time?
Crowning Moment of Funny: The song titles. "Gorilla, You're a Desperado". "Hostage-O". "I Was in the House When the House Burned Down". "For My Next Trick I'll Need a Volunteer".
"Lawyers, Guns, and Money"
"The Hula Hula Boys"
During the VH-1 documentary on Zevon's bout with cancer, he was recording "Disorder in the House" with Bruce Springsteen. Springsteen had just ended a take with a blistering guitar solo. Zevon's response? "My God. You really are him."
In Jackson Browne's eulogy for him, he relates an incident where Zevon was in an airport accidentally overdosing on a Chinese herbal remedy. His last thought before passing out: "Lord, don't let me die and have Jackson Browne write my eulogy."
Crowning Music of Awesome: When Warren was diagnosed with lung cancer and told he had months to live he started recording a final album and called in every favor he was owed. That is how you get Bruce Springsteen to play guitar and Billy Bob Thornton and Tom Petty to do background vocals on your album. The full list of all the people who performed is here.
It's said that while he wasn't nearly as famous as folks like Springsteen, Warren Zevon was a friend or associate of damn near everyone in the business. When you know you're dying of cancer and you've got half of rock music's legends in your address book, it makes sense to start calling in final favors.
Funny Aneurysm Moment: After his diagnosis, songs like "My Ride's Here," about a last ride in a hearse, "Don't Let Us Get Sick," and "I'll Sleep When I'm Dead" took on a whole new, terrifyingly sad meaning. In addition to that, the third to last album he released was entitled Life'll Kill Ya. Holy crap.
Don't forget "My Shit's Fucked Up." (Which was, fittingly enough, on "Life'll Kill Ya.")
Also, the title track mentions dying of the "awful, awful diseases." He died of mesothelioma.