In one episode Raven says, "Who would watch a show about a teen psychic." is a reference to the entire series itself.
Well, let's see. You have three options. Either you do it, you do it, or you do it!
When the exterior of the Baxter house is shown from the porch, the walkway goes to the right. But when the house is shown from the street, the porch has a stairway that goes to the left.
In episodes from Season 4, Raven is heard saying "Oh Snap! Yep, that's me!" at the end, instead of just "Yep, that's me!"