These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Grey's Anatomy
Alas, Poor Scrappy: Well, it'd be an understatement to say that the Mercy Westers were unpopular both in universe and with the fans, but I bet no one wanted to see Reed and Charles shot dead during the hospital shooting.
Anvilicious: Boy, oh, boy... This show is a poster child for this trope. In fact, the beginning and end of every episode is reserved for a voiceover by Meredith (or, occasionally, another character, if it happens to be their Day in the Limelight) highlighting the episode's particular Aesop.
Why, no, I don’t watch Grey’s Anatomy out of the corner of my eye ... and by no means do I mock that every episode ends with some patient croaking in melodramatic fashion during a montage set to Snow Patrol’s "Chasing Cars" ("If I lay here.. If I just lay here ... Would you lie with me and just forget the world?") leading to perpetual basket case Dr. Grey offering a voice over with some sort of pseudo-philosophical Chinese-cookie-worthy life lesson that the doctors learned while botching their latest life and death surgical procedure ("You spend your entire life searching for a place to call home, and only when all seems lost do you turn around and realize, you’ve been there all along") and I absolutely totally don’t mimic EKG flatline noises every time "Chasing Cars" comes on the radio.
—Jim Geraghty, National Review Online
Ass Pull: The solution to season 9's problem? Have Catherine Avery come and offer to have the Avery Foundation buy the hospital.
Badass Decay: Bailey. Gone are the days when "The Nazi" was feared by almost everyone. The interns have started calling her "Booty Call Bailey" behind her back and are more afraid of Meredith than they are of her.
A pretty extreme case is Izzie Stevens. By cutting her fiancé's LVAD wire and putting him at even greater risk of heart failure to push him up the donor register, she should've had her licence revoked and been imprisoned. Instead, she's barely punished and gets 8.7 million dollars. Though it did come back to bite her in the ass when she got fired in Season Six...
Some fans refer to Meredith as "Mary Sue Grey" or "Mer Sue". Her mere voice managed to bring a man back from a vegetative state, and she tampered with Derek's clinical trial, almost ruining his career, but was Easily Forgiven.
Bokhee the scrub nurse is absurdly popular with fans, despite the fact that she (1) has appeared in every season and had a half-dozen lines in total, and (2) is never credited, to the point that the name of her actress is not known, and most fans misspelled her character's name until it was clarified on Twitter.
Steve Mostow in some circles, mostly for being the Hero of Another Story that puts most of the show's soapier subplots to shame, and hangs a huge lampshade on it in the process.
Family-Unfriendly Aesop: Arizona's tryst with Dr. Boswell is justified by the claim that Arizona, a Control Freak, is allowed to lose control once in a while. So, because she's never cheated before, that makes it okay for her to cheat now?
If a woman beats a man to the point where he's in a critical condition and he hits her back in self-defense he is still the bad guy and shouldn't press any charges because all anyone will care about is that he hit a girl.
To be fair, Karev only said that to convince the man in question not to press charges, and not because he meant it. He's immediately called on it by Shepherd, who says it's tantamount to blackmail and that he shouldn't feel good that it worked.
"Funny Aneurysm" Moment: In the Season Six Finale episodes, one of Grey's infamous periodic disasters (this time a shooting), Meredith is explaining to Cristina what being the godmother to her child means, to which Cristina replies, "OK, so, if you and Derek are in a plane crash and die, the kid is mine?", happy that they're placing so much trust in her. It's a joking line, if a bit dark, but it's placed firmly in this category once the next disaster to strike the Grey's team comes along: a plane crash. In which Cristina, Derek, and Meredith are all involved and injured. Oh, and Lexie is killed.
In an extremely similar example, when Cristina is asked to be Sofia's godmother, Meredith tries to dissuade her by telling her that in that case, three people would have to die before she got the baby. Two of those people are involved in the plane crash, and one of them does die.
In the season 8 Valentine's Day episode, Lexie debates with herself on whether or not to tell Mark that she's still in love with him. She makes a crack about how she better do it because "if you don't say it, you bleed out and die." Guess who gets crushed by a plane a few episodes later?
Growing the Beard: A good example of growing it (season 2), shaving it off (season 4), growing it again (season 6 finale, which was widely seen as revitalizing the show), then shaving it off with the deaths of Lexie and Mark in the season 9 premiere.
Harsher in Hindsight: "Disarm," the episode that aired on 6 January 2011, revolved around a shooting at a college committed by a student named Jared. Two days later, Jared Lee Loughner opened fire on an Arizona political event, killing six and injuring thirteen others.
In the sixth episode Izzie teases George that he needs to ask Meredith out before he dies. George yells back "I'm not dying!" He dies in the season five finale and no, he never did ask Meredith out. However, he did sleep with her, she cried, it was very awkward, and he ended up meeting Callie and getting over Meredith.
Much earlier than any of that, dating back to the very first episode(!), Burke's treatment of George is... difficult to watch without being reminded that Isaiah Washington was later fired for comments he made about T.R. Knight. Seriously, he does everything but explicitly call him gay.
Demi Lovato's episode after she was hospitalized with mental issues.
In a season 5 episode, Arizona says to Alex, "I wish that you could just get organs delivered instead of having to go and pick them up, you know? I hate flying. I always feel much closer to death on a plane than I do in the OR." Come the end of season 8, it turns out her fear was justified. At least they weren't going to pick up organs on that flight.
Hilarious in Hindsight: One Season 6 episode dealt with a morbidly obese patient who was too big to fit in the scan machine. Dr. Percy suggested to get the patient to the Zoo hospital and use one of their scans, which Dr. Bailey immediately rejected and fired Percy from the case. A few years before this episode aired, Scrubs dealt with the same issue, except they decided they should use the Zoo scan, and calling out the patient on his irresponsible behavior.
In in-show example: in Season 9, the new interns are inquiring to Jo about how Owen felt her up, and Stephanie gets behind Leah and grabs her breasts, with not only no opposition, but a little help and a glance from Leah. This was quite a while before Leah decided If It's Arizona It's Okay.
Ho Yay: Almost every male character has at least one questionable moment per… almost every other male character.
In one episode Sloan and Derek fight over Avery in a way that is very reminiscent of men fighting over a girl. Lampshaded by Alex who jokes that they are arguing over who can take him to prom.
It's gotten gayer. Wayyyy gayer. To the point of art really.
One episode has Jackson break up with Lexie because he has chosen Mark over her. Though he wanted Mark as a mentor and friend and dating Mark's ex made it difficult to get close to him.
Jerkass Woobie: Alex, before moving on to Stoic Woobie. His nickname for the first while was "Evil Spawn", or occasionally "Dr. Evil Spawn", but later seasons make you feel for the guy.
Jumped the Shark: Of course, it's debated as to which point the shark jump took place. Burke leaving, all of season 4, Izzie having sex with a ghost, the Seattle Grace/Mercy West merger, or, most recently, the deaths of Lexie and Mark.
The affair between George and Izzie in Season 3 may have been the beginning of the end. The romance itself was not necessarily bad, but up until then the show had focused on Gray and Grey Morality—heck, it's even in the title! The Izzie/George relationship, in comparison, involved shilling them and Villain Balling Callie—a major shift in tone.
Like You Would Really Do It: The plane crash left Derek's hand damaged, so he was unable to do surgery, most likely forever. Several months, and surgeries, later and he appears to be making a full recovery.
Izzie was initially a successful example, with her cancer plot turning her into a very sympathetic character, but a combination of the show's excessive milking of the storyline and Katherine Heigl's behavior in real life eventually launched her right back into the heap.
Scapegoat Creator: Shonda Rhimes gets a LOT of bile spewed in her direction. So much so that the "About Me" section on her twitter reads: "I make stuff up for a living. Remember, it's not real, okay? Don't tweet me your craziness."
Izzie, due to some combination of: the Idiot Ball moment with the LVAD wire; being a Karma Houdini re: same; being the person George cheated on Callie with; the actual George/Izzie romance, after a year of drawn-out love-triangle, being a complete dud; and Character Shilling.
Special Effects Failure: The crowd holding a candle-lit vigil outside the hospital in the college shooting episode is a small group of people copied and pasted. Several people in the crowd are standing next to their clones.
Stoic Woobie: Cristina, who was damaged quite significantly by her father's death... in her hands. Alex moves to this after spending a while as the residentJerkass Woobie.
And season 7 has Cristina even more Woobie-ish after having a Heroic BSOD during an operation when a loud bang from an accident paralyzes her with fear, as a result of the hospital shooting. And more recently, her going practically catatonic in season 9 for weeks after the plane crash.
Take That, Scrappy!: Richard telling Leah Murphy that she'll never be a good surgeon and firing her, even if he did do it rather gently.
George. In the first few seasons he was the sweetest, most idealistic character on the show. All he had to do is sleep with Meredith ONCE, to finally convince him she wasn't into him, and it completely shattered his character. He became a cynical, out-and-out Jerkass overnight, sleepwalking through relationships with Callie, Lexie and Izzie, and falling behind in his work for no reason. And then they completely abandoned doing ANYTHING with him at all, to the point that C-Plots with him just involved him staring at the Case Of The Week and occasionally saying his lines. And THEN when T.R. Knight finally got fed up with it all, and could you blame him, they were prepared to put George on a bus, then pulled the old Bus Crash and killed him horribly and unnecessarily.
They Wasted a Perfectly Good Plot: Meredith's Death Seeker tendencies, easily some of her most interesting traits, are consistently glossed over and often downright ignored. Bringing them up, even in the context of encouraging Meredith to get help, usually results in the opposing party being made out to be the bad guy. Owen is a shining example, but even Derek was treated as unreasonable for not wanting to be with Meredith in Season 3 after what was essentially a suicide attempt.
Unfortunate Implications: Of the show's four LGBT characters, three of them are previously heterosexual women who only realized that they were gay or bisexual after sleeping with another woman. None of the three, it is worth pointing out, is still with the woman that made them realize this. While this is sometimes Truth in Television, it's definitely starting to strain credibility. While Callie and Erica's emerging sexualities were at least handled with a degree of realism, Leah merely shrugs off her friends' attempts to analyze her situation with a line about how her sexuality is a moving target.
Owen in seasons 8/9: Stressful job that he's really unprepared for, loses his best friend, his marriage is falling apart partly due to the abortion, becomes The Scapegoat being blamed for the plane crash which causes him to lose another friend and his part in it may cause the hospital to go bankrupt.