Continuity mistake: When Meredith and Christina lay on the grass in the park, Meredith's hands are on her chest but are by her sides in the next closeup. (00:01:55)
The Self Destruct Button - S1-E7
Continuity mistake: When Izzy, George and Christina walk over to the vendor, talking about Dr. Sheppard and Meredith, Izzy is in the middle, eating snacks from a packet. Between shots she alternates from holding the pack either up or down. (00:23:00)
Continuity mistake: When everybody is talking in the canteen, Merediths arm moves from down on her chair, to up in the air between shots. (00:09:20)
Continuity mistake: When Meredith and Christina are trying to tell Derek about Katie, he gets into the lift and the door begins to shut. In the next shot the door is back open. (00:27:55)

Continuity mistake: We see a nurse writing down "Yang, C" on the assignments board; note the handwriting. Later, when Burke notices that Christina's name is on the board, the handwriting of "Yang, C" is completely different and other minor writing differences are noticeable too. (00:27:55 - 00:33:45)
The Self Destruct Button - S1-E7
Continuity mistake: At the beginning of the episode, Izzy takes a purple plastic cup of coffee with her to work. In the parking lot she now has a coffee in a disposable paper cup. Then in the locker room, she is back to having the purple plastic cup of coffee. (00:02:25)
Continuity mistake: When Meredith puts the Hello Kitty plaster on her forehead in her car, she puts it on upside-down. When she reaches the elevator it is now on the right way up (it is unlikely she would have removed it just to place it back on the right way up.) In addition when she is in the elevator, from shot to shot the position of her fringe (and how much of it covers the plaster) keeps changing. (00:01:50 - 00:02:55)
Continuity mistake: "Flight" (8-24): At the five minute mark, Meredith, wearing scrubs, frantically leaves Christina to go search for her missing husband, Derek. Yet when we see her again a few scenes later she is wearing a jacket.

Deterioration of the Fight or Flight Response - S2-E27
Continuity mistake: At the very start of the episode when it shows Burke laying on the floor after being shot, there is a very large pool of blood with his glasses right next to the blood. But in the next shot there is no pool of blood anymore but it returns in the next. Additionally, the pair of glasses change position. (00:00:05)
Continuity mistake: You see Karev in the elevator with O'Malley putting on OR scrubs, in the next scene Karev isn't wearing his but a few shots later he is. Karev is wearing gloves, yet we don't see him putting them on.
We Are Never Ever Getting Back Together - S10-E22
Other mistake: When Meredith is talking to Kenzie about the conjoined twins, she is wearing a lab coat that says Seattle Grace Mercy West. The hospital is named Grey Sloan Memorial at this point. (00:20:00 - 00:21:00)
Continuity mistake: Meredith takes over injecting George for Alex, and right after she stands behind George, Alex leaves. Just when he opens the door, suddenly you can see Alex is behind George and Meredith is just coming in again. (00:19:55 - 00:20:50)

Visible crew/equipment: When Burke steps onto the elevator Miranda declines his offer to scrub in on the GSW, and just as Miranda admits to having a "date" that evening, a T-mark can be seen on the floor in front of Burke. (00:10:40)
Superfreak - S7-E3
Character mistake: When Meredith adds Amy's name to the board for Derek's surgery she spells Amy's last name differently than Derek's.
Blues for Sister Someone - S2-E24
Continuity mistake: When Addison and Alex are talking to Rose about tying her fallopian tubes, her necklace jumps from under or over her shirt between different shots. (00:08:45)
Continuity mistake: When everyone is in the locker room nearing the end of the episode Alex starts to shout at George. As he does, George removes his white coat twice between shots. (00:37:20)
What Have I Done To Deserve This? - S2-E20
Audio problem: When Alex pages Izzie and she comes outside, he presses her against the wall and then gives her a cupcake. When she takes it she goes "Oooh!" but her mouth is closed.
(As We Know It) (Part II) - S2-E18
Character mistake: Meredith states that she cannot remember the last time her and Derek kissed. Derek says that the last time was when they were still dating, but it was actually at the end of season two episode three, after Addison arrived in Seattle and Derek and Meredith had stopped seeing each other. (00:40:00)
Suggested correction: She is referring to the last time they kissed without any issues. The last time they were good.
Damage Case - S2-E25
Visible crew/equipment: When Izzie closes the door with blinds hanging on it, before going to sit on Denny's bedside, you can see a crewmember with their filming equipment reflected in the glass of the picture hanging behind her. (00:35:00)
It's the End of the World (Part I) - S2-E17
Continuity mistake: After Meredith puts her hand on the bomb, everyone stands up. It shows Christina and Burke standing up looking at her, But in the following wideshot Dr. Burke is suddenly crouched down again.