Hanes/Champion: official clothing of WDW, sponsor of RnRC
Nestle: sponsor of The Land
Siemens: sponsor of Spaceship Earth
Kodak: sponsor of Imagination, official film/photo paper provider, sponsor of guide maps
GM: sponsor of Test Track
HP: sponsor of Mission: Space
Brawny: sponsor of Lights, Motors, Action!
Sparkle Towels: official paper towel provider, sponsor of hand washing tips in bathrooms
Alamo: official car rental company, sponsor of TTA
McDonalds: sponsor of Dinoland U.S.A.
Coca Cola: official soft drink provider, sponsor of Club Cool, Liberty Inn and Casey's Corner
Stouffer's: sponsor of Liberty Tree Tavern
Energizer: sponsor of Star Tours
Dole: sponsor of Enchanted Tiki Room Under New Managment and Aloha Isle
There are probably more, but this is what I could do off the top of my head.
Edit: also Sylvania: sponsor of Illuminations: Reflections of Earth and the Osborne Spectacle of Dancing Lights
