Well, it's all in the title, isn't it? I like a lot of Disney artists, so it's really hard to pick just one.
If I go by the drawings only, it could be Daniel Branca, Daan Jippes, Mark de Jonge, Ben Verhagen, Marco Rota or a more recent artist, like Francesco Peinado, whom I admire very much. Also the Mau and Bas Heymans from the 1990's I like very much, but I'm not fond of their recent work.
If I go by stories, William van Horn and Don Rosa would both be in the race, although both of them are not as good today as they used to be. Also, I like most Duck-stories by Jan Kruse very much, especially when he's teamed up with Mark de Jonge or Ben Verhagen. Needless to say, I also adore the Duck-stories Jippes and Milton created together in the late 1970's.
When talking about the Mouse-universe, I'd have to say that my favorite artist (besides Gottfredson), is Cesar Ferioli. His drawings make Mickey and his gang look like the way they did in the great classic cartoons from the 1930's.
So, who's my favorite? Which artist do I like best?
...
Honestly, I don't know.