Favorites from over the years:
Carrot Ginger soup at Boma - ate here in 2004 and it is still on my All Time WDW Food Finds list
French Onion soup at Les Chefs (2012) - really enjoyed this. Thought it was good at Boatwright's, too. BOG's was just ok for me (theirs is veg broth, Les Chef's and Bwright's are beef)
Clam Chowder at Cape May - this was also 2004, no idea if it's still as good
Beer Cheese Soup at Le Cellier (2013) - the one thing that would make me go back there. It would be awesome if Canada would put in a Quick Service with this soup.
And the two previous posters are really making me want to try lunch at GF cafe next year...