Super Mario World/Choco-Ghost House
This is one of the only two Ghost House in the game without a secret path, the other being the Vanilla Ghost House. All you need to do is exit through two yellow doors, and you're done.
On this level, beware of the moving gaps in the floor. This room is made even harder by the Fishin' Boo ahead of you that can make it much harder to jump over the moving gaps.
Use the ghost blocks to get to the door in the second phase...be careful because they turn into ghosts if you turn away. There is also a bouncing diagonal line of ghosts that you may need to avoid. If you can't use the ghost blocks to reach the high door, you need to spin-jump on the ghost line to be repelled to the door.
Go for the finish line.