We saw loads last month over 30 and the kids filled thier books with signatures. To be fair we saw a lot of them in Inventions and Cafe Mickey at dinner time (highly reccomended for character interaction) and lunch with the princesses. Also staying in the Empire State Club meant we had characters at breakfast and teatime daily.
In the parks we went to the scheduled meet and greets at Princess Pavillion, Meet Mickey Mouse, Duffy by the Storybook Store, Pooh at Casey's Corner, Jack Sparrow by the Chalet au marionette, Jack and Sally by Phantom Manor, Mickey in WDS, Buzz and Dasiy Duck in Toon Plaza.
As well as that Chip n Dale were inside the door of WDS pretty much all day. Also in WDS we saw Aladdin and Jasmine, Gaston, Mulan, the wicked witch etc.
In WDS the characters who appear in the Cars n Stars Parade will normally be out at various points by Cinemagiue, Animagique, Playhouse Disney Live etc and we saw a lot of them here.
For us it's all about the characters so I book all the character meals that I can as least then guaranteeing some character interaction