afreed said:
With all due respect to Monte's work, he was really a latecomer to Planescape--while he wrote a bunch of adventures, he didn't do much of the core setting material; only the Astral and Inner Planes books, Planewalker's Handbook, and the MC3. (Unless I'm forgetting something.)
For the recond, you did:
Hellbound, Faction War (which had a lot of Sigil source material beyond just the adventure--in fact, it was originally conceived as a sourcebook, not an adventure), Planes of Conflict, and, as you say, some adventures: Tales from the Infinite Staircase, Dead Gods, Great Modron March (I don't know if I'd call that a bunch).
Not that it's a contest, but I did, in fact, write more Planescape material than any other designer (although only by a little), and was the designer on the team the longest. (I was not the member on the team longest, though, that would go to editor Michele Carter.)
Compare this to some of the people I view as the core of the team: Colin McComb (Planes of Law, Planes of Conflict, Faces of Evil, Hallowed Ground, Outlands Primer, the Torment CRPG), Wolfgang Baur (Planes of Chaos, Planes of Law, In the Cage),
You can hardly leave out Ray Vallese, who not only edited a lot of products in the line, but wrote Faction War, Uncaged, and Something Wild. There's also Andrea Hayday, who managed the line the longest, as well as others who contributed a lot like Dori Hein, David Wise and Lester Smith.
And of course, Zeb Cook created the setting, after all.
Michele Carter (edited half the line),
A very conservative estimate.
and, of course, DiTerlizzi.
Again, while Tony did a lot of work, if you're going to include artists, Robh Ruppel and Dana Knudsen probably did as much to shape the line, and artists like Adam Rex and Randy Post did virtually as much work on PS products.
And I didn't even mention Rich Baker, Bill Slaviscek, Bill Connors, Bruce Nesmith, Skip Williams, Sue Cook, Tim Beach, Miranda Horner, Bruce Cordell and... well, as you can see, a lot of people worked on this great product line.