In this thread, I put my foot down and give you the gun-to-my-head best song each of these songwriters ever wrote, with the stipulation that I reserve the right whenever I choose to get an 'added cut' and give you one from the band they were in and one from their solo work.

First up, Tom Petty WITH the Heartbreakers (important because Mike Campbell did the music for this song):

Tom Petty WITHOUT the Heartbreakers:

Van Morrison...this is impossible, really, but since there's a gun to my head, this is the song:

Elvis Costello: it's either "You Tripped At Every Step" or this, and it probably has to be this.

Paul McCartney with The Beatles? Here you go:

Paul McCartney solo? If you haven't heard this song already, I pity you:

Brian Wilson...again, a heartbreakingly difficult choice, but for me it's always been this:

Bob Dylan? Ha, good luck reducing Bob Dylan to just one song. But here I am, doing it:

Pete Townshend with The Who: basically impossible as a task, but again the gun is cocked and I must choose, and so I choose this. No vocals! All instrumental!

Pete Townshend solo? I am torn because "I Am An Animal" and "Slit Skirts" are both so immensely moving, but end of the day, it has to be the greatest song about addiction and a desperate prayer for redemption ever written.

George Harrison with The Beatles? I could be a clever lad and pick "Long Long Long" but c'mon, we all know it's this:

George Harrison solo? There's more to that career than you might suspect (LIVING IN THE MATERIAL WORLD is a wildly underrated album, even if it went to #1), but yeah, it comes from ALL THINGS MUST PASS:

Bryan Ferry (and Roxy Music): oh this was actually an easy one, even given that I love Roxy to death. But they never topped this.

Brian Eno (solo, obviously, he never wrote a song with Roxy). A lot of great choices, and man I'd like to pick "Baby's On Fire" with that great Manzanera solo, but ultimately it's Robert 'Chuckles' Fripp w/one of most moving guitar solos in rock history:

David Byrne (with Talking Heads, don't really know his solo work)? Again, it's a "pick your joy" situation. But this will always be the one for me, where for one moment he finally seems to work through his personal weirdness by diving into THE GROOVE:

Mick Jagger? Well, unless you want to hand off partial credit to Mick Taylor, nothing is ever going to top this song he brought to the Rolling Stones as a solo track:

Keith Richards? With a tip of the cap to "All About You," "You Got The Silver," and "Before They Make Me Run", only a monster would deny that it's this, his most iconic star-turn:

Peter Gabriel with Genesis: this is tough, since they were such a collaborative songwriting group during the early years, everyone pitching in. But the best PURE Gabriel-only Genesis track? It's probably this, one of the few he did live as a solo act:

Peter Gabriel solo? Ha, this is somehow EVEN TOUGHER, because I might as well just name the entire PETER GABRIEL 3 album and then mic-drop. But again, the gun is loaded and aimed at my temple, and this is the one I want on the desert island:

David Bowie? Oh dear. Some people are Ziggy-era fanatics, some people are Eno-era fanatics, and I understand both arguments, but the best song he ever wrote and recorded will always be the one about the girlfriend-eating television set:

Randy Newman is one of America's greatest songwriters, and he has written so many songs that people could argue about as his best. But this is his best for me: both literal and metaphorical, about the forgotten people.

Robbie Robertson: again, maybe I could just cite half the songs on THE BAND (the brown album) but the bullet's in the chamber so it's this, a song that comes from a place out of time.