In "The Grasshopper Experiment" (S01E08), Sheldon sees Raj's Indian date and she reminds him of Princess Panchali from the Indian folktale, The Princess & the Monkey. He wonders out loud how often you see a beloved fictional character come to life. Howard says that they do at Comic-Con. Disneyland and those that you pay for that come to your front door.
In "The Large Hadron Collision" (S03E15), Leonard is trying to get Penny to guess that they are going to Switzerland together to see the Large Hadron Collider. One of her guesses is that they are going to Disneyland to ride the Matterhorn bobsled ride. Her next guess is that they are going the same thing at Disney World, though they don't have that ride.
In "The Spaghetti Catalyst" (S03E21), Penny takes Sheldon to Disneyland after he hears that she is going with her friends. Leonard gives Penny suggestions on how to take care of Sheldon at Disneyland, as he is familiar with the events of Sheldon eating junk food and throwing it up after he goes on Space Mountain. Also he is afraid of Goofy, but has no trouble with Pluto. Later Penny admits that he did get sick on Space Mountain and Sheldon is seen having a nightmare about Goofy.
In "The Werewolf Transformation" (S05E18), Sheldon is driving people more crazy than usual because his usual barber is no longer available. Penny wants to give him a haircut as she mentions others things she has done for him like taking him to Disneyland.
In "The Contractual Obligation Implementation" (S06E18), Raj is asking the girls where he should take Lucy and they suggest Disneyland and then then get excited about going themselves. While playing hooky, Bernadette wants to have a Disney princess makeover, while Penny thought they would get drunk and throw-up on the rides. Each of them want to be Cinderella; however, Bernadette gets aggressive and tells them that she is going to be Cinderella. Later she tempts Howard in her costume, while Penny gets all apologetic in front of Leonard dressed as Sleeping Beauty getting Leonard all excited. Amy as Snow White tries to get Sheldon to kiss her to wake her up.
In "The Bon Voyage Reaction" (S06E24), both Bernadette and Penny remind Leonard about when he got seasick after being trapped on the "It's a Small World" ride. Penny wants to make sure he has plenty of Dramamine since he will be on a ship in the North Sea for three months.
In "The Locomotion Interruption" (S07E15), Sheldon is dealing with Officer Hernandez in Kingman, AZ after he is robbed of all of his possessions on his train adventure. Several times he asks about his stolen property. The officer claims that they are doing everything they can while he is munching on Doritos. Sherlock Holmes used cocaine to sharpen his senses; however, Sheldon claims that the officer's Doritos are probably going to do the same thing. Doritos were first introduced at Disneyland in 1964.
In "The First Pitch Insufficiency" (S08E03), the gang is attending a LA Angels game to see Howard throw out the first pitch. While the others are planning on enjoying the entire game, Sheldon wants to watch the pitch and then head to Disneyland to see Mickey's Soundsational Parade. Amy tells him that if he stays, she'll get him some cotton candy and a bobble-head doll.