Grey's Anatomy has been through a lot of cast shakeups over the years, but for a show that's been on the air a whopping 10 seasons (and counting), an impressive number of its original cast members are still around.

Now that the show has been on the air for a decade and we're having to face the fact that Sandra Oh (Cristina Yang) bid her farewells at the end of Season 10, we thought it would be a good time to take a second to reflect on how much the original characters who have lasted this long have changed. After all, a decade of learning, loving, and nearly dying at least once a season has some pretty big effects.

Meredith, Derek, Cristina, Alex, Bailey, and Richard have all undergone huge transformations. From Richard getting his drinking under control to Cristina learning to connect with her patients, Bailey softening from her "Nazi" mode to Meredith becoming far less dark and twisty, they've all grown.

But who's changed the most? That's up to you to decide. So vote in our poll, and then sound off with your opinions in the comments below!

Grey's Anatomy Season 11 premieres Thursday, September 25, at 8 p.m. ET on ABC.