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.
And You Thought It Would Fail: Many people had doubts that this series would be a success. Instead the Skylanders series has crossed the $2 billion in sales threshold, with over 175 million toys sold since 2011, it makes the series one of the top 20 highest-selling video game franchises of all time!
Broken Base: There are some fans that are willing to at least give it a chance or actually like it, despite the negative outcry from a lot of them. Some are happy that Spyro's personality is supposed to be like his Classic Self.
Cynder broke the base again. Legend fans were quite pleased, Classic fans weren't. Many fans wanted a clean break from previous continuities...
There's a displeasure within both the "Classic" and "Reboot" Spyro fans that this series is less of a Spyro reboot and more of a series that includes Spyro in it. The fact that there doesn't seem to be a new Spyro game coming out anytime soon leaves fans worried that the series will befall the same faith as its rival, Crash Bandicoot.
Some Skylanders even break the base. Sprocket for example has some people hating her just because she looks "too human", while others think she's a refreshing change of pace in adding some diversity to the teams. Some merely dislike her because they already have her and they have to wade through dozens of Sprockets to find what Skylanders are available in the stores next.
While it hasn't caused large-scale drama in the fandom, there is quite a bit of debate over wether Toys For Bob or Vicarious Visions have done better for the franchise. Toys For Bob developed the original Skylanders game (Spyro's Adventure) and its sequel, Giants, while Vicarious Visions developed SWAP Force (as well as the 3DS version of Spyro's Adventure and the various iOS/Android games). Although SWAP Force includes features such as new bonus modes and jumping, some fans dislike the story, lack of Heroic Challenges, or how some older Skylanders were nerfed. Others feel more neutral about it and think that Toys For Bob are better with story and creative assets, but Vicarious Visions are better at technical aspects and game design.
A lot of fans also disagree with each other about which of the 3DS games is the best. Some like the pacing of Spyro's Adventure better than that of Giants or SWAP Force, which are more slow-paced. The former was developed by Vicarious Visions, while the latter two were developed by n-Space. At the least, it seems most people agree that SWAP Force was better than Giants.
The upcoming 3DS version of Trap Team is developed by Beenox with the help of Toys For Bob, yet another set of developers, so it might divide peoples' opinions further.
Critical Dissonance: Fans were really not looking forward to it, and many are making a big deal about how little respect they have for the game or hope in its ability to sell. Critics, meanwhile, are often very warm to the new game, taking it for the toyetic kids' game that it is, and quite like it.
Demonic Spiders: Missile Mauler trolls in Swap Force. Unlike most ranged enemies, their regular attack fires a homing missile that redirects towards you once and deals a HUGE amount of damage (120-ish on Medium difficulty). They also tend to be positioned on elevated areas or on the far end of the arena, which means that they're going to fire that missile at least once.
Spyro has become this because he's, well, Spyro. He's no more important than the other characters but has a major following.
Flashwing is also pretty popular, probably due to being voiced by Tara Strong.
Out of the villains in Trap Team, Wolfgang is probably one of the most popular, mostly due to his cool design, voice, and the fact that he is a werewolf that uses rock and roll as a weapon. Another villain that's gained some popularity is Broccoli Guy, not only for his hilarious design and voice, but also because he's incredibly useful in gameplay.
Fridge Brilliance / The Dev Team Thinks of Everything: Jet-Vac flies using the vacuum device on his back, which depending on your upgrade path is limited duration... however using his secondary attack (the vacuum mode on his gun) starts to refill it.
Fridge Horror: Like you, Kaos and his mother are portal masters... however, Kaos's mom actually uses her powers to Interface Screw, and speaks directly to the player - she knows how to fight a fellow portal master, and is Genre Savvy enough to attempt to attack the player. Just imagine if Kaos learned how to do this...
In Trap Team, he gains the ability to do just that. The horror is mitigated by the fact that he isn't very good at it, instead pulling random junk through the portal.
From Spyro's Adventure, we have Terrafin and Ghost Roaster who are really good at dodging, Hex who can set up a super-powerful wall while she safely fire away from behind it, and Boomer whose ground pound attack hurts a lot of targets at once and stuns.
From Spyro's Universe, Tech Skylanders are really good for the Sky Defense minigame, where their machine gun Limit Break can mow down multiple mooks with ease.
From Swap Force PvP, we have Bumble Blast. His bees can be fired at a good rate, home in on the enemy, and hit more than once. He also has honey and mines which make the opponent slowed for some time and also makes them take more damage from bees. Then there's Jolly Bumble Blast, who is Bumble Blast wearing a Christmas hat that boosts his speed and armor by a huge amount.
Dune Bug in Swap Force's Story Mode. An early upgrade allows his Dune Balls to trap up to 5 small/medium enemies (bypasses shields and hits flying Rip-rotors), then he can roll them off the edge for a One-Hit Kill. As Skylands is a World in the Sky, he has many opportunities to do so, and if there isn't he can fire the ball at a wall to stun the trapped enemies. As such, the only Mooks Dune Bug usually has to worry about are Geargolems. This ability is mostly useless in Pv P, though.
Chef Pepper Jack in Trap Team. He's absurdly powerful, being able to rain down explosive peppers over a wide radius (each of which does 120 splash damage) at a mind-boggling pace (roughly 1.5 second cooldown, 5 per shot), precision kill enemies with his fire breath AND rapidly move about the battlefield with his whisk charge. Additionally, upon completing his Wanted Poster, the mitigating factor of his summon time is tripled in length. He turns Arena Battle's and Kaos Challenges into cakewalks at best and "Mash Primary Attack To Win" exercises at worst.
Eon's Elites. Super powerful versions of fan favorite characters from the first game, such as Spyro, Chop Chop, and Trigger Happy. Noticeable traits are triple stats and having their card values cap at 500 while Trap Team series characters only go up to 250. By about level four, this Troper's Elite Spyro had over 1300 health!
Growing the Beard: Some people believe that in between Giants and Swap Force, the series started to take itself a little more seriously. Giants started adding a lot of well-known voice actors to the cast. (Just take a look at the Trivia page!) The toy designs became more detailed, and the games started gradually adding more to the gameplay, such as the ability to jump. Not to mention, the levels of Swap Force are not only better looking than in Giants, they are much more full of secret areas, some of which are relatively well hidden.
Additionally, Swap Force began featuring more nuanced combat styles among the Skylanders themselves. While still in simplistic, kid friendly forms, Stance Systems, Status Buffers, Beastmasters and more are present, rewarding players who take a more strategic approach to combat.
Trap Team furthers the growth artistically, featuring a slightly upgraded version of the graphics engine from Swap Force, the return of several fan favorite characters from Giants, and the figurines continue to become even more beautiful and intricate. While Swap Force was certainly no slouch in the figurine department, the Trap Masters are gorgeously painted and modeled, with craftsmanship rivaling that of several hundred dollar collectors figures.
For some, making fun of that one Skylander who the stores always have a ton of that you already have.
Scrappy Mechanic: While the figures certainly cater towards the collector demograph and is the Dancing Bear, the Merchandise-Driven aspect has created a minor annoyance of a Scrappy Mechanic - the fact that certain Skylanders are more rare than others, and that not all of the Skylanders are released at once. This can lead to certain Skylanders who the stores never seem to run out of and other figures that the stores never seem to carry. Not to mention, certain Skylanders never got a series 2 or series 3 rerelease, meaning that as stores carry less Spyro's adventure packs, it becomes harder to find the non-commonplace Series 1 Skylanders, same with the battle packs.
Sunburn and Ghost Roaster deserve special mention, as their figures are only available in the Dragon's Peak and Darklight Crypt packs - which have been out of print for several years and, consequently, become much harder to find in a brick-and-mortar store. Furthermore, Darklight Crypt was fairly rare to begin with, leading to sightings of it in secondhand stores for almost $200.
As mentioned by Chris Bores, certain Skylanders tend to be purchased immediately by collectors, who then sell them on ebay or Amazon for inflated prices. This makes certain figures a little more rare.
For some time, Ninjini was so rare that stores which carried Skylanders reported a ratio of one Ninjini figure out of forty other Giants being shipped. Like Spy Rise and Stink Bomb mentioned below, it was not uncommon to find her online for four times her retail price.
The Mystery Gates and villains requiring unknown elemental traps in Trap Team. You cannot access/trap them. Period. At least, not until the new elemental characters are released. Some might enjoy that they'll have more to do later, but others might get annoyed at these until then completely unknown villains showing up. Bound to be a moot point upon their release however.
On the subject of Trap Team, the fact that elemental gates must be opened by Trap Team members. It certainly encourages the collection of the new characters, but it seems a tad unfair when Swap Force allowed you to bypass the dual gates via co-op and can make the other Skylanders seem less needed. Also like with the Mystery elements, as of this writing, Magic gates are an impassible brick wall.
Self-Fanservice: just check at Deviantart, you'd be surprised how much arts there are about naked Stealth Elf, often with very exaggerated curves when compared to the skinny action figure.
Hex got some of this too; werheas her actual dress is rather sober and cover everything but her face and fingers, you will probably easily find art of her in Stripperiffic goth attire with Absolute Cleavage, when she even wears something. And of course, don't expect her to have decayed skin or anything similar : they apparently forgot she was suppposed to be an undead.
It doesn't take long for Ninjini, Chill and Sprocket to get fan-serviced either. As a deviantART member once reacted:
"God dammit....you just cant stop yourselves, can you? Gotta draw EVERY HUMANOID Skylander like she's some kind of god damn porn star!"
Shipping: while the game doesn't provide any visible romance between the Skylanders themselves (due to their personalities and relationships never being explored except in the biographies and trailers), this hasn't stopped the fans from already imagining some shippings. Aside from the obvious Spyro/Cynder due to them being based on Legend of Spyro, Flameslinger/Stealth Elf seems to have become quite popular (logically due to the fact both are from the same species).
Even Les Yay have been imagined already, mainly with Stealth Elf/Hex.
That One Achievement: In Giants, only one of a character's "Quests" cannot be achieved in single player — it requires winning 10 PVP matches, and you can't Gold-rank the figurine without it. Do you have friends to challenge?
In SWAP Force, one of the Portal Master achievements requires you to own at least one Sidekick... because you got it, right? Surely the toy stores haven't decided to stop carrying all the sidekicks...
Alleviated as of Trap Team, which featured a re-release of all eight original sidekicks, along with eight new ones, as a core aspect of the toy line.
For collectors, there is that one figure that you can never find - it's always online for a much higher price than you're willing to pay for it.
Tear Jerker: The Machine Ghost's Disney Death in Giants.
Sonic Boom's backstory is painful to read.
That One Sidequest: Some of the Heroic Challenges can be a nightmare for certain characters. For example, Drobot's HC requires the player to kill 100 green Chompies while avoiding the purple ones (although you are forgiven if you kill just one). Thing is, there is quite a ton of the purples in the dungeon, and they are also aggressive. Good luck trying to complete this challenge with characters with ranged weapons (you can accidentally shoot a purple off-screen), a wide-ranged attack (the purples will gang up on you), or a Giant (who automatically trample any Chompies that get close).
Any challenge marked "Warning! This can be tough!" has the potential to become this. Like Drobot's challenge above, these often require precision, destroying some targets while avoiding others; and some Skylanders are just no good at avoiding collateral damage.
Ugly Cute: About half the skylanders. Kaos and Glumshanks may also count.
In-Universe, the Wilikin are a race of wooden doll people who creep out almost everyone who interacts with them.
Viewer Gender Confusion: If you never read her bio, you might be forgiven for thinking Sonic Boom is male in the first game, despite the focus on using her eggs/hatchlings in combat. In Giants however, she's given a clearly feminine voice.
The Woobie: Sonic Boom. She went to hell and back to find a safe place to have her eggs and some rotten wizard decides to put a curse on them so they always return to their eggs after a short period, meaning she'll never see her babies get to grow up. This didn't stop her from teaching them to kick butt, however.
You have to feel a little bad for Night Shift as well. He got banned from boxing, his favorite sport, all because there was a change in rules which outlawed teleportation. It's implied that he has no control over his abilities.