Credit: Ron Tom/ABC via Getty Images Photo: Sadie Leads the Interns' Learning Club in Grey's Anatomy Season 5, Episode 8, "These Ties That Bind"

4. The interns' "learning" club
Sadie proved herself to be one sick puppy when she cut herself open so that she and the other interns could "learn." This brand of masochism kinda made us glad so many of the newbies got fired. Moving on...

3. Deer rescue
Poor Izzie sweeps the top three spots on this list. Remember when she and her interns were sent to the parking lot to save a deer? Yeah, we do too. Let's not dwell.

2. Izzie's ghost sex
One of the biggest WTF storylines is that of Denny's ghost. Izzie seeing him in hallucinations? Acceptable. Izzie having raucous sex with said hallucinations? Unacceptable! Yes, it led to a powerful storyline later on, but it was fully alienating for a while there.

1. Gizzie

When Izzie slept with George, it was shocking. When they started dating, it was just weird. Honestly, we didn't need to see the aftermath of Izzie's bizarre shower sex fantasy — and their unfortunate nickname makes us feel like we should pull their relationship out of a turkey before cooking the bird. Blech!

Credit: Scott Garfield/ABC via Getty Images Photo: Izzie Encounters Denny's Ghost in Grey's Anatomy Season 5, Episode 7, "Rise Up"
As much as we love Grey's, we're willing to cry foul when something preposterous happens. The following ill-advised moments and storylines did not go down easy — at all:
Credit: Ron Tom/ABC via Getty Images Photo: Meredith Sees Denny's Ghost in Grey's Anatomy Season 3, Episode 17, "Some Kind of Miracle"
5. Meredith's near-death experience
First of all, everyone knew that Meredith couldn't die. Second, up until that point, the show had stayed in the practical realm, not really delving into anything supernatural. And yet there Meredith was in a heavenly waiting room, somehow sensing that her mother had died at the same time. Really, Shonda? Really?

10. Alex and Callie's hookup 
Grey’s writers, you can't just retroactively decide that two major characters slept together years ago because you need a source of drama. That's cheap and sloppy. (Okay, Alex is also cheap and sloppy, but still... )

9. Icicle'd
When Cristina slipped on the ice, it was funny. But when she was then impaled by a falling icicle, the laughter ended quick. Turns out it was a pretty wussy wound, so it appears this was another ploy for the advertisements. ("Say what?! An icicle impales someone? Who?")

8. Enabler Joe
Why was Joe the Bartender, who otherwise seems like a stand-up guy, giving Richard drinks? He knew Richard was an alcoholic — or so it seems, considering "club soda" was their code for hard liquor. Was he following some sort of sacred bartending covenant? We just don't understand.

7. Meredith and George's tearful hookup
Meredith knew she didn't want it. George knew Meredith didn't want it. Yet they did it anyway, for about five seconds. It was all kinds of icky.

6. Rose
Seriously, the woman joked about carrying Derek's child (just so ABC could tease fans all hiatus long with the soundbyte) and then "accidentally" stuck him with a scalpel. Good riddance — McRebound had to go.