Almor: Poor Almor never had a chance. Pre-Wars era, the Prelacy was one of the goody-goodiest places in the east. It was a fine buffer for Nyrond and the Great Kingdom so naturally it needed to be destroyed and taken over by an animus warlord.
Blue: I used to think this town was ridiculously named by Gygax (as if they aren't all that way). In retrospect, it's now one of my favorite ports for pirate based storylines. Old Blue-port has grown on me.
Chendl: I'm not a big fan of Chendl being the capital of Furyondy. Not sure why exactly, but I think it's location. Canon says Dyvers used to be the capital, and now its a free city for whatever reason. Did this occur before or after the king moved his capital to the north? Closer to the danger of Iuz. The Greyhawk Wars nearly destroyed this city. Maybe next time.
Dorakaa: Now Iuz's capital is a different story. There it lies on the opposite side of Whysetil Lake from Furyondy, flaunting its evil. When Iuz the Evil and City of Skulls came out I was stoked. This city is the most dire place any PCs could find themselves and here we finally had a module and sourcebook for going there. I only wish the maps and keyed locations for Dorakaa were on par with the City of Greyhawk boxed set because this place has to be full of adventure.
Elredd: I cannot help but think of the town of Eldred near my home when I see this on the map.
Fax: Unlike Blue, this Wild Coast town hasn't grown on me. Blue's name can be justified. I have no answers for this one.
Gradsul: This port city is an enigma for me. It isn't the capital of Keoland, but I do believe its the largest city there and given its location, Gradsul is most important. Why do we not have more canon information on this place then? In a perfect world, Carl Sargent would've got Ivid the Undying published then moved on to Keoland to develop this place. I know Keoland got the royal treatment in the Living Greyhawk Journal eventually, but really Gradsul like Dorakaa could be a setting starter all its own.
Hokar: I used this little known Sea Princes town in my latest campaign (576 CY). Running pre-wars era, I had to develop pretty much everything for it including a map to use. We had a blast with Hokar, so I plan on going back there someday. It's got a nice remote location that is suitable for a locally focused, sandbox style game.
Irongate: Speaking of setting cities, Irongate is also in my top five places deserving of its own sourcebook. There was big plans for Irongate long ago, but in the end a short overview article was all that Erik Mona could graciously fit into Dragon #351 before Paizo lost the rights to WotC.
Jotsplat: I just like saying the name of this place. And I pronounce it Yot-splat for the record.
Kester: Oh yes, I haven't forgot about you my old friend. New material is buried deep within my mind waiting to come out.
Lopolla: I used to set things in Lopolla all the time. Ket is the crossroads for cultures in the World of Greyhawk thus Lopolla is really the best place to find anything or anyone right?
Maure Castle: Before Rob Kuntz's megadungeon came out in Dungeon #112 I really knew little about Maure Castle except what was in Mordenkainen's Fantastic Adventure. Both mods are among my favorites (moreso than any Greyhawk dungeon) and my only regret is not resolving the dungeon to the end. Eli Tomorast waits.
Nevond Nevnend: Say this city name ten times in a row.
Onnwal: I never did much with this small country in the old days, but since Living Greyhawk Onnwal developed it (with LG-Naerie they were the best group) this place is now rich in map detail.
Port Toli: I have big plans for this city in my Sea Princes campaign. Any and all maps or material on this place I will accept otherwise I will give it the Hokar treatment.
Quag Lake: Quick thought. Why didn't/couldn't TSR put a Quag Keep on the Darlene map?
Rel Astra: Another city in my top five for a setting sourcebook. I once drew a massive graph paper map of this city for a criminal-themed campaign I was going to base there. It never took off and since then I've seen some nice fan made maps of this city online. We need more Rel Astra.
Scarlet Brotherhood: In the Greyhawk reboot, they need to stay mysterious and threatening. The Scarlet Brotherhood was a decent sourcebook but if you tear out the Hepmonaland and Amedio parts its just a pamphlet. Let's make this a place to investigate.
Tiger Nomads: Over the years the Wolf Nomads got a lot of canon love (and in Rose Estes' novels wolf love, ahem). What do we really know about the Tiger Nomads though?
Uleks: You thought I was going to talk about Ull I bet. Hah no. The County and Duchy of Ulek (not so much the Principality) are places I've rarely if at all set any games in. I think a "small race" themed campaign would be fun to set in the Uleks.
Valley of the Mage: Vale of the Mage did get its own entire sourcebook somehow. I'd like a redo on this one however.
Welkwood: I have a few ideas on using this sylvan forest someday, tied to my recent campaign foray into the Suss Forest. It involves fading lands, fey and unicorns. Yes, I said unicorns.
Xamaclan, etc: Did you know damn near every canon location starting with an "X" is in The Scarlet Brotherhood sourcebook? I didn't till I looked it up in Zavoda's Index. Interesting stuff.
Yeomanry: Little known fact, in 576 CY the Yeomanry is ruled by Crispin Redwell (F10/C5) but by 591 the ruler is a guy named Marius Lindon (Rg10). As the Yeomanry is a democratic republic, I assume Crispin's term limit was up.
Zeif: Lastly, anyone wanting to run a full on Baklunish campaign needs to find a rare copy of Living Greyhawk Journal #5 featuring Fred Weining's amazing survey of the Sultanate of Zeif. The maps alone are worth the trouble.
That was fun. I need to do this again sometime.