The main issue The One With Fake Monica has comes from its inability to say or do anything meaningful, despite its obvious attempts to come across as poignant and touching.
The episode comes in two parts, the first of which follows Monica as she befriends an adventurous criminal who's stolen her credit card, and the second of which finds Ross having to give up his monkey Marcel after he reaches full maturity and starts making a hobby out of humping everything and everyone around him.
With Monica's story, the episode does worryingly little to justify her friendship with Fake Monica, a woman who's presented as adventurous and cool but is really pretty terrible and not the kind of person you'd want in your life. The Marcel debacle is much of the same, basically watching like thirty minutes of cheap sex humour.
There's something fun and emotionally engaging lurking within the premise on this one, but it's lost under weak recurring gags, unbelievable character motivations, and a strange lack of development for all those involved.
Season two is a great instalment of sitcom fun, cementing Friends as a major hit and featuring some of the best episodes of the show. That being said, not every episode is a homerun, and season two's weakest moment would definitely have benefitted from not existing at all.
The One With Russ takes place after Ross blew his chances with Rachel after writing a list of comparing her to his girlfriend, Julie. The episode finds Rachel trying to move on by dating a guy called...Russ. Not only do they have similar names, but they're both David Schwimmer with different hair.
The entire premise is too ludicrous to find funny or endearing, and the too-cheesy episode makes no attempt to fix its silliness when Russ and Julie (both having been dumped) fall in love in its final moments.
That's all bad enough, but the episode also has a side-plot in which Monica starts dating "Fun" Bobby, and realises his upbeat persona comes from his alcoholism. The episode then plays Bobby's addiction as a mean punchline, and makes Monica look like an awful human being in the process. Gross.
A strong case could be made that The One With Phoebe's Ex-Partner is the worst episode of the entire show. At the very least, it's certainly a cautionary tale in how not to write comedy. Or write anything, for that matter.
There are three major developments in the episode: One follows Chandler as he starts dating Joey's ex Ginger and finds out she has an artificial leg; one follows Phoebe as she reconnects with - and then gets conned by - her old music partner; and one finds Ross getting unnecessarily jealous over Rachel's colleague, Mark.
Between the poor taste of Chandler and Ginger's brief relationship, which comes complete with a series of cringe-worthy jokes about disability and body shaming, and Ross's beyond aggravating fragile ego, the episode is both incredibly tasteless and painfully low on laughs.
How the episode manages to waste its entire ensemble (and a game guest star in Sherilynn Fenn) is really quite impressively frustrating, as is the way it sets up three separate plots and botches them all. How it was greenlit is a mystery.
Friends actually did quite a few clip shows during its run, and none of them are good. In fact, they're all pretty terrible, and this trend of creating pointless filler episodes out of the most boring of developments started in season four's The One With The Invitation.
The set-up is that Ross has sent invitations out for his and Emily's wedding, but is conflicted about inviting Rachel. This causes him to have flashbacks throughout their most defining moments. On the other side of the episode, Rachel wonders whether she should go to the wedding, and has her own trip down memory lane.
That's it, in a nutshell - just half an hour of flashbacks to old episodes, bookended by Ross and Rachel looking all wistful and unsure. It's so dull, pointless, and lacking in any kind of forward progression that it's actually quite difficult to write about. It's barely an episode, and does literally nothing to justify its existence. Moving on.
Friends' fifth season spends far too long droning on about Ross and Emily's failed marriage whilst attempting - with noticeably forced results - to make Emily look like the bad guy and Ross look like some kind of endearing hopeless romantic we should all suddenly be rooting for.
The One With Chandler's Work Laugh is no exception to this trend. Though by this point Ross and Emily are over and done with, the news that she's engaged again causes Ross to pursue a very one-sided relationship with Chandler's ex, Janice. This pairing is both silly and unjust, and is more awkward than it is amusing.
Throughout the episode, Ross' attempts to look like a tortured good guy with a broken heart just come across as annoying and repetitive, hammering home just how boring his latest character development has become.
The other side of the episode, which follows Chandler and Monica as they bond with Chandler's boss, does little to save this nonsense, and once more features humour which maybe should be funny, but actually comes across as incredibly dumb and narratively pointless.
Isn't it telling that many of Friends' worst episodes feature Ross at his most unapologetically awful? The One With Joey's Fridge is one of his worst outings by far, and to make the episode worse it even finds a way to make Joey unlikable.
But first, Ross' stuff. In the episode, Ross is sent into a spiral when he finds out his college girlfriend Elizabeth is going on spring break. Because of his crippling, over-the-top trust issues, he thinks she's going to cheat on him, and so conspires to keep her from going away.
Elsewhere in the episode, Joey's fridge breaks and he keeps trying to push his friends into it so he can blame them for its faults and con them out of some money. It gets old fast, and honestly isn't that funny to begin with.
In the end, nothing really works with the episode, not even Chandler, Monica and Phoebe's sub-plot about finding a date for Rachel's upcoming work event, since they all come across as controlling and infantile throughout. And the final shot revealing Ross went with Elizabeth for spring break is just...so, so wrong. Ew.
The single most infamous Friends episode, The One With Chandler's Dad hasn't just aged poorly - it was already deplorable even when it aired in 2001. The "product of its time" argument might somehow work for certain fans, but it's not nearly enough to justify how ugly and offensive the episode really is.
In it, Chandler and Monica travel to Las Vegas to invite Chandler's estranged father to their wedding. It turns out his dad is actually a trans woman going by the name Helena Handbasket, a lifestyle choice that Chandler treats as utterly embarrassing, and the show itself turns into one, big punchline to a joke no one made.
The episode doesn't stop there, though, instead doubling down on its comments about sexuality by having Joey debate whether men can feel masculine in women's underwear. It's about as funny as it sounds.
This, added to the cringe-inducing portrayal of Chandler's transgender father and an uncomfortably unfunny sublot following Ross and Rachel as they try to flirt their way out of a speeding ticket make The One With Chandler's Dad an absolute disaster, and one best left avoided in future.
For the sake of avoiding repetition, this list has tried not to focus too much on clip shows, but even so it's hard not to shout-out The One With Joey's Interview, a filler episode so uneventful and dull that it's genuinely difficult to pay attention to.
Though it starts with promise by having Joey sit down to an interview with a soap magazine, it quickly devolves into unfocussed flashback sequences detailing the highs and lows of his career, most of which have very little bearing on the trajectory of the interview.
Although it's marginally interesting to see how Joey's career has progressed through the years, the episode ultimately has pitifully few things to say outside of "Joey says dumb things and gets in trouble for them a lot, hahahahahahaha."
Much like season four's The One With The Invitation, The One With Joey's Interview can easily be skipped without missing anything of note, and therefore stands as the worst episode in a season full of terrible plotlines.
Friends' ninth season is its weakest by some margin, so it's admittedly difficult to pick just one for this list. The One With Christmas In Tulsa is another clip show well worth skipping, and The One With The Male Nanny is an awkward stab at gender politics with few redeeming qualities.
That being said, neither of these episodes are nearly as poor as The One With The Sharks, which features two major storylines, neither of them as funny as they clearly think they are. On the one hand, Monica comes to believe Chandler is turned on by sharks; on the other, Ross tries to salvage Mike and Phoebe's relationship.
The whole "Chandler watches shark porn" drama is simply a car crash of a premise, cringe-worthily lazy and tough to comprehend how on earth it even got made. It's hard to watch, and even harder to understand why the writers would make Monica act so wildly out of character.
If that wasn't enough, Ross' attempts to help Mike and Phoebe through a rough spot comes complete with odd accents, over-the-top plot twists, and the general sense of pointlessness that taints the entire season.
The sitcom's final season is barely better than its predecessor, with many poor episodes to choose from that could go here. But none are as lazy, aggravating and just plain awful as The One Where Ross Is Fine, an episode that once more makes Ross look like the world's biggest tool, without any attempt to redeem him.
Things start promising, with Ross walking in on Joey and Rachel kissing. It looks like the episode will turn into a much more serious one than what we got, full of hard-hitting drama and honest truths that put their relationship and Ross' reaction to it into perspective.
Instead, it turns into the Ross Show, with David Schwimmer giving the most over-the-top, painfully awkward and depressingly unamusing performance of the entire show, as Ross spends the half-hour speaking in a high-pitched, cartoony whine and forcing Joey, Rachel and girlfriend Charlie into the world's worst dinner.
Not only does Ross' loud attempts at comedy get old fast, but he also comes across as an unreasonable, awful friend, refusing to put his ego aside for one second to accept the romance of two of his closest friends. It really hurts to watch this one.