We just got back from a trip with our 15 month old son. He went on all of the Fantasyland rides, even Snow White, with no problems. I think he would have been fine on HM and PoC, but we thought our 3 y/o would be afraid, so we didn't even try. He wasn't bothered by the darkness in any of the rides. We took him on Spaceship Earth and Imagination, which are both pretty dark.
It's A Small World, the carousel, Pooh, Dumbo, the safari, Primeval Whirl, and the Playhouse Disney show were his favorites. He really reacted to a lot of stuff, especially Pooh and Playhouse Disney (he's a big Bear fan).
He wasn't crazy about the characters at first, but warmed up to them as the week went on.
He also loved the parades!
Our 3y/o loved everything in Fantasyland, but needed to be told ahead of time if a ride was dark. She didn't like Peter Pan the first time she rode it because she didn't know it would be dark. She rode it again another day and loved it since she knew what to expect. She loved the characters and parades.
Good luck and have a great time!
