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.
Broken Base: The rift was first created in Fans vs Canons and was widened further during Cursed Islands and All-Stars. Mainly divided along the lines of supporting either positive or negative characters. Mainly condoned on the author's part as he appreciates differing opinions.
Ker fans versus Wrecker fans. There have been debates, debates, and more debates about the two. The fact that they were the two finalists the public was voting for to win Season 7 didn't help matters.
As for the seasons themselves, Cursed Islands, All-Stars, and Battle of the Tribes fit the bill quite a lot.
Villainous winners such as Melanie and Marius; supporters say that they were great players who just happened to have a darker shade of morality and deserve recognition for their games despite their less than desirable ethics, while naysayers have thrown Villain Sue accusations towards the former and criticized the morals of the latter.
Juiced Up and Claus are easily the most divisive characters of Season 11. Either you think they are very funny fail villains, or you think that they are total annoyances who made it way further in the game than they deserved to. There is no middle ground.
Cargo Ship: Violet x Tree and Popper x Ootsies (Tootsie Rolls).
Complete Monster: Prescilla/Bonnie in Season 9. Fortunately, she gets an epic downfall to end all epic downfalls.
Bradlyn from Season 11, who killed his own son to escape Death's List. SWSU has stated that he's even more evil than Bonnie.
Creator's Pet: Minerva, Beth, or Gatemaster might fit. Either way, they're all voted out early on All-Stars.
Bonnie. While she was very popular in Season 9, thanks to the fact that she was perhaps the most vile and horrifying villain in the series and got one hell of a downfall to go with it, she is relatively less popular in Season 10 thanks to somehow managing to pull off moves that she shouldn't be able to, taking every opportunity to brag about how awesome she is, and having no discernible motivation besides just being a disgusting human being who outlasted several more popular characters. Ironically, not unlike Russell Hantz. Although she has been humiliated a number of times, she had another downfall, and her Creator's Pet status was later acknowledged by Eli.
She is also an in-universe one. The producers in the series allowed her to get away with way too much during both of her seasons.
Jackie was accused of being the former in Battle of the Tribes.
Elimination Houdini: Minerva in Season 4, Cherman in Season 9, and Bonnie in Season 10. All of them have been on the chopping block numerous times and yet managed to survive by either Manipulative Bastardry or having someone more threatening voted out over them.
Ensemble Darkhorse: Popper, a Katamari Damacy fan character who can only communicate with signs and short words, was the original notable Ensemble Darkhorse for this series. He made it onto the All-Star season despite being the fifth voted out on his original season.
In a popularity poll that had every contestant from the first 11 seasons, Montana was the winner. Then again, she always was popular among the readers.
Flame War: Hoo boy. In recent seasons, this has been a major problem within the fandom, with at least one major war taking place per season.
The flame wars in Season 11 broke the comments record several times over before the major individual responsible for them got suspended on deviantART.
Fridge Brilliance: At first you'd think that Marius giving up the ability to win individual immunity in Season 5 would be stupid. As it turns out, this twist saved him when people assumed they could take him out at any time and kept him in until the finals, where he won.
Fridge Logic: After her elimination, Denise claims to have played the perfect under-the-radar game. Yet by all accounts (except by the camera), she was a motor mouth who didn't know when to shut up. How exactly is that playing under-the-radar?
Hate Dumb: Some characters seem to get a lot of unnecessary hate from certain users. Bitsy is a prime example of one of the characters.
Hilarious in Hindsight: Sometimes, characters or fans say things that turn out to be quite ironic later on. An excellent example of this is the comments on this comic with a later commentator even saying, "A lot of people are eating their words right now."
Baxter is considered to be Russell Hantz before Russell Hantz; guess who shows up four seasons later...
This scene is averted in Season 10, where Phil comes back after losing 200 lbs.
One-Scene Wonder: "Oooooohhhh, I'm an evil talking buuuuush..." is pretty much the only reason Ella has a fanbase.
Parody Sue: Ventious, who has almost absolutely no flaws, and his entire tribe relies on him to win challenges for them because he's apparently so good at everything. Naturally, Chrii takes advantage of the fact that the whole tribe relies on Ventious and gets rid of him using a hidden immunity idol, which basically causes the entire tribe to crumble apart once he's gone. He did return for Battle of the Tribes but the author seems to be making a conscious effort to avoid this trope for him this time around, with him being unable to avoid his tribe being reduced to just two members, having the mother of all Clingy Jealous Girls in Ryuia, and admitting that he actually likes it better when he's not the Jesus of his tribe.
Zachary. He's a young master strategist that everyone around him loves and admires. He leaves first.
The Scrappy: Oran, the whiny little kid who complains constantly and cannot do anything, and PJ, who turned into an insufferable Jerkass after an elimination went as planned.
Chloe, especially in Battle of the Tribes where she managed to become more hated by the fanbase than Bonnie.
Artemis from Season 11, at least on deviantART. While some people have argued that she would have been a subpar character either way, it is also true a lot of the hatred comes from her creator getting furious about her not succeeding and being loved as much as he intended. This has led quite a lot of people to consider her a Mary Sue based on her creator's intentions.
Seasonal Rot: Season 5 hit a snag in the series thanks to the generally lower character quality and a very polarizing winner, but it ultimately recovered. Season 8 was also a low point due to the lack of Character Development, lower character quality to earlier seasons, and a easily predictable winner. One of the reasons pinpointed for this fall in quality is directed at the characters being fan-submitted, and thus harder for the author to write with, but this has been addressed as of Season 9 by mixing up the author's characters with fan-submitted ones.
Take That, Scrappy!: Artemis returned for the Season 12 cast release, now overweight. Her frantic insistence that she was the "true winner" and had played perfectly (a parody of her creator's treatment of her) impressed neither Jeff nor the actual winner.
Further (spoilery) explanation: The author said that he wanted Season 8 to be the story of how two players' intended goat (Melanie, to Heinz and Matt) ended up unexpectedly beating them in the end, which was the reason for Melanie having a relatively easy ride to the merge because Heinz and Matt were too focused on each other to see her as a threat in contrast to the other "negative" winners (Skylar and Marius) who came close to being voted out several times. Unfortunately, this ended up coming across as "show how cool Melanie is for doing all these secret manipulations and how idiotic Heinz and Matt are for not realizing this" to some readers, especially at the final Tribal Council where it became painfully obvious that Melanie had won with Heinz and Matt being called giant liars and idiots by the jury and Melanie getting little to no flack from the same jury in spite of having been behind most of their ousters- once again in contrast to Skylar and Marius, who were both savaged by at least one jury member and whose wins were very much in doubt even after their final tribal councils- which made many readers label it as "Just give Melanie the million".
Vindicated by History: Cursed Islands is viewed in a much more positive light these days, especially when compared to Midway Island or Battle of the Tribes.
Win Back The Crowd: After a season which was critically panned by pretty much everyone, Season 9 was welcomed with open arms and is considered to be on par with Season 3.
Season 11 is also generally considered to be a return to form from the previous season.
The Woobie: Driz, Bitsy in Season 2, Lucky, Iris, Chaona, "N" in Season 3, and Cherman all count.