21 'ER' Episodes That Every 'Grey's Anatomy' Fan Needs To Watch

The title of this episode is a nod to the film 9 1/2 Weeks. Dr. Greene (Anthony Edwards) and then-wife Jen spend the day in bed together, a sequence reminiscent of the early days of Dr. Meredith Grey (Ellen Pompeo) and Dr. Derek Shepherd (Patrick Dempsey). Dr. Peter Benton (Eriq La Salle) has some issues with his aging mother, which also may remind Grey's fans of Meredith's struggles with her own mother's health throughout the series.

ER always portrayed County General as a serious place, but this is one of the few episodes where viewers get to see the doctors goof off a bit when the ER is quiet during a blizzard. It's reminiscent of when the Grey's interns had their own fun.

ER fans got to see the doctors and nurses outside of County General occasionally. In this Christmas episode, Nurse Carol Hathaway (Julianna Margulies) hosts a holiday party for the staff and it might remind Grey's fans of Izzie Stevens' (Katherine Heigl) big party in the Season 1 episode "Shake Your Groove Thing."

Directed by Anthony Edwards, ER spends this episode focusing Dr. Susan Lewis (Sherry Stringfield) in a therapy session after losing custody of her niece Susie to her troubled sister Chloe. Like how Grey's puts us in Meredith's mind, this episode puts us in Lewis' head for an hour.

ER's likely version of Meredith's "pick me, choose me, love me" speech is Dr. Greene's plea to Dr. Lewis to stay in Chicago, rather than move to Phoenix to keep an eye on her troubled sister and beloved baby niece Susie. Unfortunately, Lewis heads to Phoenix, but later returns to the series in Season 8.

Remember how Grey's Anatomy's George O'Malley was identified as a John Doe who was hit by a bus? He writes "007" in Meredith's hand (an inside joke from the first season) to signify who he is. ER had a similar twist: In this episode, surgical intern Dr. Dennis Gant's (Omar Epps) is identified as a trauma patient when his pager goes off and the ER works to save him — but it's too late.

Both ER and Grey's Anatomy have done documentary-style episodes. ER's episode aired live on both the East and West Coasts in 1997.

This ER episode has a lot of small details that may remind you of Grey's Anatomy. Hathaway opens her free clinic (like Izzie once did), Carter deals with an intern crisis (like many of the doctors on Grey's do), and Greene heads into an ill-advised hook-up with desk clerk Cynthia (Mariska Hargitay).

In an act of defiance that would make Izzie Stevens proud, this ER episode features Dr. Doug Ross (George Clooney) administering an an ultra-rapid detox to a methadone-addicted baby. Meanwhile, a love triangle between Dr. Anna Del Amico (Maria Bello), her ex Dr. Max Rocher (James Le Gros), and Dr. John Carter (Noah Wyle) takes shape.

For a few episodes, Dr. Greene becomes McDreamy to ER chief Dr. Amanda Lee (Mare Winningham) in a truly random storyline. In this episode, it's revealed that Dr. Lee isn't even a doctor, but she is Dr. Greene's stalker.

Grey's Anatomy never shied away putting interns and residents through their own traumas, and the same was true for ER. In this famous ER episode, Dr. Carter and his medical student Lucy Knight (Kellie Martin) are stabbed by a patient as the rest of the ER staff has a Valentine's Day party.

A cornerstone of Grey's Anatomy is romantic reunions and this episode served as the reunion for one of ER's most central couples: Dr. Doug Ross and Nurse Carol Hathaway, who lived happily ever after in Seattle.

This is another ER episode with several storylines that may remind you Grey's. Both Nurse Abby Lockhart (Maura Tierney) and Dr. Jing-Mei Chen (Ming Na) deal with some drama related to their mothers, while Dr. Kerry Weaver (Laura Innes) realizes she might be attracted to a woman doctor (much like how Dr. Callie Torres realizes her sexuality in Grey's). Dr. Greene begins showing symptoms of a malignant brain tumor (which might remind you of Izzie's own battle with cancer).

Lots of TV shows have done Rashomon-style episodes, which show multiple perspectives to the same events, and both medical dramas are no exception. This ER episode may remind you a bit of the similarly formatted Grey's episode "I Saw What I Saw."

Grey's Anatomy often has episodes that are set in the field rather than the hospital. This ER episode is one of many that follow Dr. Carter and Dr. Luka Kovac (Goran Visnjic) working in the Congo.

Both Grey's and ER docs don't seem to have good luck around aircrafts. In this ER episode, Dr. Robert Romano (Paul McCrane) meets his untimely end when a helicopter crashes on the roof of County General.

Grey's reflected the experience of a veteran trauma surgeon through Dr. Owen Hunt (Kevin McKidd) and ER did so as well through Dr. Michael Gallant (Sharif Atkins). This ER episode contrasts the lives of Gallant working in a combat hospital in Iraq and his girlfriend Dr. Neela Rasgotra (Parminder Nagra) working at County General.

Like the doctors of Grey Sloan Memorial Hospital, the County General staff also dealt with a shootout that occurred in this Season 12 episode of ER.

Grey's Alex Karev isn't the only doctor on a medical drama to have legal troubles. This ER episode focuses on Curtis Ames' (Forest Whitaker) malpractice lawsuit against Dr. Kovac.

Both medical dramas balance moving forward and saluting their original cast of characters. ER revisited some of its beloved original characters in this nostalgic episode, which features Carol Hathaway and Dr. Doug Ross working with a grieving woman (Susan Sarandon) to donate her grandson's organs. One of those organs winds up going to none other than Dr. John Carter, who is awaiting a kidney transplant and encounters former mentor Dr. Benton.

The Grey's Anatomy episode "If/Then" explored Grey Sloan Memorial's alternate universe. This ER episode did something similar in Dr. Neela Rasgotra's dreams, where she tries different courses of action with a patient in order to save the patient's life. Dr. Elizabeth Corday (Alex Kingston) also makes an appearance.

Now that ER is streaming on Hulu, get to watching Grey's fans!