Credit: Ron Tom/ ABC

In the most recent episode of Grey’s Anatomy, Sarah Chalke was awesome as she guest starred as a single mother with a child who had a very serious and very rare illness. This got us thinking: what other celebrities have appeared on Grey’s as patients?

Here are some of our favorites:

Abigail Breslin. In Season 3, Episode 3, “Sometimes a Fantasy,” Abigail was adorable as she played a patient convinced she had superpowers because of her inability to feel pain. And Alex was pretty cute, too, when he read comic books to try and relate to her.

Seth Green. Seth played a patient who had a tumor removed in the Season 4 episode, “Crash Into Me.” He tries to put the moves on Lexie, but his carotid artery bursts and covers her in blood. Not the best way to flirt. We were so sad when things went south for him!

Credit: ABC

Demi Lovato. As a patient believed to be schizophrenic, Demi appeared in this serious role in Season 6, Episode 22, “Shiny Happy People.” It turns out she isn’t schizophrenic after all -- instead, Alex discovers she had a hole in her inner ear that made sound much louder to her than to everyone else.

Scott Foley. Scott played Henry, Teddy’s patient-turned-husband in a recurring role that spanned fifteen episodes in Season 7. Scott’s appearance made us nostalgic for the days of Felicity, and it broke our hearts when it was up to Cristina to save him in surgery, and he died.

Mandy Moore. Mandy played a patient ready to get rid of her colostomy bag in the Season 6 finale, “Death and All His Friends.” She quickly transformed from patient into Bailey’s right hand when the shooter made his way into her room. She later returned the next season to get the surgery she was never able to have because of the shooting and died on the table. Cue sobs for Bailey (and us too!).

Looking ahead, we're sure former One Tree Hill star Hilarie Burton will make quite an impression on viewers as a craniofacial specialist who visits Grey Sloan Memorial to work on a case in penultimate episode of Season 9. 

Who are your favorite Grey's Anatomy guest stars? Sound off in the comments!