We have met various combinations of two or three characters: Mickey, Minnie, Goofy, and Pluto. They will not tell you what characters are there, so it is a surprise when you enter. My kids love this character meet because it is private.
You get one free photo per account per day. We do this every time we are in Epcot between 1:30 and 4:30-- usually 3 times per trip.