As a CM at Disneyland, and a regular park goer I am continually entertained at alternate names that folks come up for attractions, shows, and locations. Here are some common ones, feel free to add.
Main Street U.S.A- Downtown Disney
World of Disney- Disneystore
Haunted Mansion- The Haunted House
Matterhorn Bobsleds- Magic Mountain
Monorail- the train
King Arthur's Carousel- the merry go round
Tower of Terror- the lift, the escalator (not common, but fun)
I'm sure some other regular park goers, and custodial/attractions CMs have a ton more.