L'Artisan des Glaces in Epcot is really the only great ice cream in any of the parks, IMO. If I had to pick for the other parks - Hollywood Scoops in HS - they sometimes have really good specialty shakes, Dino Bites in AK has amazing ice cream sandwiches, and MK - I think I'd have to go with Sunshine Tree Terrace - I'm partial to orange dole whip over the pineapple. Storybook Treats and Auntie Gravities sometimes have specialty shakes or floats, but otherwise they're just basic soft serve, nothing special.