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.
Mary Sue: Plenty of them show up in the application process. Some make it onto the island, but far less than there used to be.
Narm: Due to the written medium, a poorly-placed typo or the like can utterly ruin a scene's mood. Also, the gore in some scenes is so hilariously over the top and childish (not to mention some of the one-liners...), that it's almost impossible to take seriously. On the other hand...
Nightmare Fuel: ...some scenes use gore in a skilled enough manner to give the reader a serious case of the willies. A classic example would have to be Damien Carter-Madison's death scene, where he is heavily implied to be dragged into the gates of Hell by his former classmates. It's... unnerving and frightening, to say the least.
Paranoia Fuel: It's all too easy to start applying the mindsets of characters to your own classmates.
Critical Research Failure: An early scene with Andrew Swainson has his murder attempt stymied by leaving the safety on. He's carrying a Glock, a handgun famous for having no manual safety devices whatsoever.
Alas, Poor Scrappy: The death of Liam Black was considered to be well-written, and genuinely saddening, in spite of the fact that the character was extremely unpopular whilst alive.
Memetic Badass: Bobby Jacks, who in-game managed to headshot a student from behind without looking at them. This led to tales of Bobby ricocheting bullets Revolver Ocelot-style (which led to the nickname Bocelot,) killing students from several threads away, and firing his gun in v3 and killing a student in v4.
Moe: Sierra Manning, a cute emotional girl whose cuteness is only amplified by her lisp.
This trope could also easily explain why Orn "Dutchy" Ayers is so popular on the board. Dutchy is an Icelandic, free-lovingcomic book nerd who watches soccer and cries Tender Tears over the plight of third-world countries among other things. Add in his in-game posts, which makes many handlers see him as The Woobie, and his habit of wearing a Pointless Band-Aid over his nose, and you have a character who most of the board adores. Which makes his mental scarring and subsequent death all that more painful.
Portmanteau Couple Name: The broship of Liam "Brook" Brooks and Jason Harris is generally referred to as "Brason", while Garry Villette and Saul Fetteralf are commonly referred to as either "Garul" or "Gaul".
Base Breaker: Gavin Hunter is either an interesting concept with flawed execution or an affront to all humanity, depending on who you ask. It doesn't help that his handler ragequit the site after his escape attempt failed.
Cargo Ship: As an officially canonical example from Virtua, no less: Sycanus Appletin and her teddy bear are... rather close. At one point she is shown making out with it.
Evo can easily invoke this. The characters have no friends, some people get permanently and horribly mutilated before the game even starts and even if they win, there's a chance if their change was too great they'd never let them go home and they'd be an experiment forever.
SOTF-TV is an inversion, in that the Lighter and Softer comedic elements caused some handlers to feel less concern for the characters.
It's the Same, Now It Sucks: Second Chances, again, as reusing old characters who were mostly handled by the same writers, combined with the same basic plotline as SOTF Main, limited its novelty value for a lot of readers. It wasn't helped by most of the characters coming from V4, the version that took place just before Second Chances, which meant that most of the characters had just been seen in action a few months ago.