Fantasyland has many characters during the morning/lunch hour, specially in front of Bella Notte (Pinocchio & Gepetto, the 7 dwarfs, Suzy & Perla), near Alice's Labyrinth (Tweedledee & Tweedledum are always there, sometimes the Mad Hatter & the rabbit too, and if you're very lucky, Alice and the Cheshire cat).
In Adventureland, just next to Au Chalet de la Marionette, you can meet Hook & Smee, and sometimes Peter Pan & Wendy. I've also seen Baloo & King Louie all around Adventureland, but usually around Hakuna Matata restaurant.
In Discoveryland, next to Star Tours, I've seen Stitch, but also Chip & Chop in futuristic costumes.
Also, yesterday Ii saw Belle (with her first dress, not the gown) next to the well, in front of the castle.
If you ever see a line of people where there's not an attraction, or a big crowd, check, because sometimes you just don't see the characters and you might miss some of the best. I've queued for longer for Hook than Peter Pan, Belle, Pluto or Goofy, just because Hook was in a very visible place and the rest were kind of "hidden".
And now they have between 2 and 3 CMs with the characters, so they can better control they queue. People will always try to jump the whole queue, but CMs don't let them. I've seen some get pretty serious/angry.
Also, face characters really take their time. When young kids were meeting Bella she spoke to them, sat on the floor, asked them how their day was, who they'd met, how pretty their princess dress was... They're really nice.