Character mistake: Episode 6.12, Moving The Chains: Marcus tells House that he and Eric were arrested for stealing a car, he was 16 and Eric was 14. He also says that his brother never did anything criminal after that. In season 1, we were told that Eric was 16 when he was arrested for stealing a car.
Factual error: House is playing 'Metroid: Zero Mission' on his Gameboy at various times. The Metroid series does not feature space monkeys, nor are there distinct levels. The sounds coming from the game in the show do not match it in real life, and Samus morphing into a ball is most definitely not a failure state.
Continuity mistake: As House describes the lady's symptoms, in the front shot Chase has a small book/pamphlet in his hand. The camera changes to a side shot in the middle of House's description and suddenly the book is on the table and no longer in Chase's hand. This happens right in the middle of House's line and Chase doesn't make any quick movements to account for this discrepancy.
Continuity mistake: As Cuddy is making the deal with House, how much time off from Clinic duty for a week off his vicodin, while the camera is behind Cuddy you can see there is bright sunshine on House's head. The shot switches to a camera behind House and now his head is shaded.
Visible crew/equipment: In the scene where House and Allison are walking down the stairs, they round a corner and we see a dolly shot down a short hall with a glass wall in front. During this shot, a camera, cameraman, and dolly are visible in reflections on the glass.
Continuity mistake: House is about to inject Ezra Powell (Joel Grey) with what is supposedly a lethal dose of morphine. In the shots where they pan out to show House addressing the room at large, the syringe is very full, almost completely. When they zoom in on House holding the syringe, it is only filled a fraction of that much - maybe a quarter to a third. This doesn't happen just once, but every time they switch between shots.
Factual error: In episode 414, "Living the Dream," the patient Evan is given a nerve function test. We see Kutner and Taub performing the test by puncturing Evan's legs with needles. Modern nerve function tests actually rely on electrical impulses from a small computerized device, with no needles necessary.