Picking only designers of which I own 2 games seriously limited options.
Donald X: Dominion and Kingdom Builder
Chudyk: Glory to Rome and Innovation
Knizia: Battleline, T&E
Martin Wallace: Automobile, Discworld
Mattt Leacock: Panemic Iberia and Pandemic Legacy
Corey Konieczka: Game of Thrones 2nd Ed, X-Wing
Alan Moon: Ticket to Ride, Incan Gold
Stephan Feld: Castles of Burgundy, Aquasphere
Uwe Rosenberg: Bohnanza, Agricola (oh god can I keep Patchwork too)
Antione Bauza: 7 Wonders, Takenoko
Only ones I left out are Alex Pfister, Ted Alspach, Andrew & Kristin Looney, Richard Breese, Rob Daviau, Richard Garfield, Inka & Markus Brand, Sid Sackson, ok maybe a few others. That list was longer than I thought.
Wow I also don't own any other Freideman Friese game besides Power Grid. Shame.