The Hot Troll Deviation - S4-E4
Continuity mistake: When George Takei and Katee leave Howard's bedroom, in one shot Howard is clasping his hands together, in an instant they are spread out completely. With no time to move them. (00:04:25)
The White Asparagus Triangulation - S2-E9
Continuity mistake: When Leonard is helping Sheldon open the jar, the red napkin which he left on the couch where he was sitting changes position or vanishes in every shot.
Continuity mistake: During the whole opening scene, the way in which Leonard holds the letters in his hands keeps differing.
The Lizard-Spock Expansion - S2-E8
Continuity mistake: At the very beginning, Leonard's Diet Coke keeps changing position without anyone touching it.
The Pork Chop Indeterminacy - S1-E15
Continuity mistake: When Sheldon says that his sister was sent to spy on him, his arms are behind his back. Camera cuts and they are now at his side.
Continuity mistake: When Leonard and Sheldon are talking with Penny during the scene where she is being allowed to sleep on their couch, the pullstring on her hooded jacket keeps alternating from hanging loose to being caught inside the top of the jacket. (00:07:40)
The Vegas Renormalization - S2-E21
Continuity mistake: When Leonard and Raj are getting ready in the bathroom, Raj picks up a tube of shampoo/conditioner off the bathroom bench with his left hand. However, in the next shot, Raj has nothing in his left hand and the tube is back on the bench, with no time for him to replace it between shots.
The Gothowitz Deviation - S3-E3
Continuity mistake: When Penny is making French toast and Sheldon walks into shot, the edges of the toast are not covered in egg whilst the rest of the toast is. About 30 seconds later, Penny asks Sheldon if he wants French toast and the edges are still not covered in egg. The shot cuts to Sheldon. In this shot we can see Penny's hands to the far edge of screen and fully raised showing us that she hasn't dipped the edges of the toast in egg yet. But in the next shot, we can see the whole of the toast is covered in egg, including the edges of the toast that were clear a moment earlier. (00:00:20 - 00:00:50)
The Robotic Manipulation - S4-E1
Continuity mistake: When Penny says "let's just finish our dinners" she raises her fork twice. (00:16:45)
The Spaghetti Catalyst - S3-E20
Continuity mistake: When Raj and Leonard are sitting on the couch, Leonard is holding Watchmen and Lost in Space in his left hand and Young Sherlock Holmes in his right. In the very next shot when Leonard turns his head after Raj speaks, Watchmen has disappeared.
The Bath Item Gift Hypothesis - S2-E11
Continuity mistake: When Leonard gives Penny her christmas gift, as she unwraps it she tears the paper off so that most of the box is exposed. In the next shot much more of the wrapping is back intact and differently positioned. (00:19:40)
The Closure Alternative - S6-E21
Continuity mistake: Sheldon and Amy are talking while drinking tea together. The entire time, Sheldon has his hand next to his other hand, but in an individual shot, his hand is suddenly on his other wrist.
Suggested correction: There is a moment when he puts his hand there. So nothing wrong here.
The Lizard-Spock Expansion - S2-E8
Continuity mistake: When Leonard is talking to Penny in the laundry room; as he walks forward to ask her about whether him dating Stephanie is wrong, the box of washing powder on the machine behind him alternately has its lid closed or open. (00:14:00)
The Barbarian Sublimation - S2-E3
Continuity mistake: When Leslie and Sheldon are talking to Dr. Eric Gablehauser in his office, in one shot Eric throws a piece of paper onto the desk behind him (next to the computer.) Through the rest of the scene, this piece of paper keeps changing position. (00:09:00)
Continuity mistake: In the early episodes, Leonard is depressed and buys cat stuff. He comments that he has taken in to account Sheldon's asthma with a hyper allergenic cat. Later in the series it is Leonard with asthma and Sheldon who gets all the cats.
Suggested correction: Presumably Sheldon also buys non-allergenic cats.
The Financial Permeability - S2-E14
Continuity mistake: When Sheldon asks Penny if he lent her enough money, the container he is holding opens on its own. (00:09:25)
The Vartabedian Conundrum - S2-E10
Continuity mistake: When Stefanie and Leonard are talking in bed towards the end, Stefanie's arm moves from on her head to on her pillow instantly. (00:16:30)
The Euclid Alternative - S2-E5
Continuity mistake: When driving down Euclid Avenue, the background is constantly changing between shots. In one shot it's a busy main street and in another it's a suburban street. (00:04:50)
The Euclid Alternative - S2-E5
Continuity mistake: When Penny turns on to Euclid Avenue, the car behind her just vanishes into thin air. (00:03:50)
The Countdown Reflection - S5-E24
Continuity mistake: After Howard and Bernadette are pronounced husband and wife, when they kiss the camera angle switches to an overhead shot, but as it zooms out (to a digital image) things change - such as the configuration of the rooftop, or things move - such as the cable dishes, or things even vanish - such as air-conditioning units.