Broken Base: The announcement that TJ Miller would be leaving the show split the fanbase. While many saw it as a perfect opportunity for the show to escape from the repetetive rut that they believed it had fallen into, others believed that removing Erlich would strip the series of one of the most central aspects of its identity. This was further complicated by TJ Miller's own admittance of being firmly in the former camp, along with his claim that the series lost nothing by removing him from it.
Pete Monahan, Pied Piper's cut-rate trial lawyer. His personal anecdotes are bizarre and oddly audacious, but are delivered in such a matter-of-fact way by Matt McCoy. He also displays a genuine sense of duty to Richard that few in the series do.
Billionaire douchebag Russ Hannmen proved such a funny character that the show keeps bringing him back for brief cameos long after his importance to Pied Piper concluded.
"Funny Aneurysm" Moment: During an amusingly awkward conversation, Gavin compliments Peter Gregory on how healthy he looks. The actor who plays Gregory died of lung cancer before the season finished shooting.
Many of the equations seen on screen are genuinely relevant to the topics being discussed. Mike Judge even mentioned being happily surprised at being able to understand the roomful of dicks equation and being able to picture in his head the type of curve the show's technical director was describing (Mike Judge has a physics degree and used to work as a computer engineer).
The title sequence is a fairly accurate (albeit highly stylized) representation of the tech market with each season's sequence being adjusted to show the ever changing trends.
A lot of the things referenced in the show are specific to the culture of Silicon Valley and the tech industry in general.
At TechCrunch Disrupt, Erlich requests dramatic spotlights "like Pride Fighting." This is a reference to PRIDE Fighting Championship, a now-defunct Japanese Mixed Martial Arts promotion that featured bombastic lighting and pyrotechnics during each fighter entrance.
In the episode "Sand Hill Shuffle," Erlich's has a T-shirt with binary on it. It translates to "BITCOIN."
Guilfoyle has a coffee mug reading "BLACK COFFEE" with coffee beans that imitate the logo of Black Flag.
The 51% attack seen in "Fifty-One Percent" is a real form of attack on blockchain based technologies (though the show embellishes it somewhat).
He Really Can Act: T.J. Miller shows real dramatic acting chops in the Season 3 finale as Erlich is furious at Richard betraying his trust and tells him off.
Ho Yay: Given that the show's only primary female character is Monica, who's been definitively established as platonic, there's bound to be some of this.
Jared, with his unconditional devotion to Richard and often wistful expressions, comes across as an Ignored Enamored Underling. In recent episodes, the two have had more interaction to fuel a Twice Shy interpretation of their relationship. Since the revelation that Jared does, indeed fuck, Richard's reactions could be read as just a tad more.... jealous.... than Dinesh's envy or Gilfoyle's 'huh'. The Season Four finale has a penitent Richard showing up at Jared's door and having an emotional conversation in a way typical of romantic comedies. And having Richard go into what seems very much a small fit of jealousy over the peals of women's laughter in Jared's house.
Idiot Ball: If the people at Intersite only wanted Pied Piper to download the files from their server to compress, why did they give them write access as well, enabling the accidental deletion of 1/3 of their content? This goes against the principle of least privilege, which is widely considered very important in network security. Making matters worse, apparently they don't even have any backups.
It's the Same, Now It Sucks!: While the show is still considered very good by the fans, many of them have grown increasingly restless at the show's constantly hinting that it's going to majorly shake up the status quo, only to go right back to the same setup as always within an episode or two. The announcement that TJ Miller would be leaving after Season 4 actually caused some excitement as the crew would finally be forced to make a major permanent change, with Miller himself expressing frustration at the plot stagnation and the hopes that his exit will stir the pot.
Special Effect Failure: Gavin's triumphant moment over the Hooli board is undercut a bit by his standing next to an obvious CGI elephant.
They Changed It, Now It Sucks!: While TJ Miller's departure excited many fans who believed that the show had begun to grow stale and sought a change to the status quo, just as many believed that his contributions to the tone of the series were too important to get rid of.