I took my video camera on every ride at
Disneyland - some won't let you film, like California soarin or the 3D rides, but they don't search your bags and confiscate cameras, just keep it in the bag under your seat.
I took it on splash mountain and filmed without any protection and it didn't get too wet - but I covered it up for Grizzly river run as EVERYTHING gets soaked on that ride.
I left my stuff with my wife for screamin so can't remember if there were any restrictions on this.
Otherwise I filmed on Pirates, Haunted mansion, Pooh, everything in fantasyland, Big Thunder, Pooh, etc, etc.
One thing you will discover is most of the dark rides like Peter Pan, Pinocchio etc are not worth as they just come out, well, dark!