Milt Schmidt is definitely the best from Kitchener, Scott Stevens is second. Other stars include Daryl Sittler, Woody Dumart, Earl Seibert and Dutch Hiller. Doug Risebrough and Howie Meeker had good careers too.
The only played I can find from Hespeler is Paul Woods.
The best played from Guelph is probably Kirk Maltby. Lou Fontinanto was undoubtedly the toughest/meanest play from Guelph. Mike Hudson both Brian MacLellan had fairly long careers.
Mel Bridgman is the best from Trenton, George Ferguson is second.
Agreed that Syl Apps is the best from Paris. Only other player I can find is Jay Wells.
If you count Joe Thornton as being from St. Thomas, he's definitely their best player (most sources list him as being inside London though). Then he'd be up against Eric Lindros.
Mr. Hockey is the only player from Floral, as far as I can tell.
Lots of great playes from Ottawa, agreed that Potvin is best and Yzerman is second. Other stars (no particular order): Mike Gartner, King Clancy, Doug Wilson, Frank Boucher, Aurel Joliat, etc. There are several other Hall-of-Famers but I won't list them since I would like to pick some of them in the All-Time Draft #5...
Gretzky is obviously the best from Brantford (he'd be the best from any city except Parry Sound...). Bill Cook is second. Doug "I... am... Iron Man" Jarvis is probably third. Chris Gratton and Pat Hickey were other good players.
Orr for Parry Sound. Other NHLers were Neil Belland, Terry Crisp and Gary Sabourin.
St. Sault Marie's top three are Phil and Tony Esposito, and Ron Francis.
Kamloops, in addition to Recchi, produced Bert Marshall, Tim Watters and Doug Lidster.