Xanth/YMMV


 * Damsel Scrappy: Millie in Castle Roogna.
 * Dude, Not Funny: Putting gay men in strait jackets. This troper wanted to give whoever came up with that one a nutcracker, If You Know What I Mean.
 * Oooooooooh, yes it is funny. Keep in mind that homosexuality used to be considered a mental illness, and still is in several countries. There are still many people who profess to be able to 'cure' it with therapy, and gay people who go to those things and force themselves, or are forced into, straight lives. The entire concept is ridiculous and deserves to be mocked with an Incredibly Lame Pun.
 * Except that it's the only mention of gay people in the books that this troper can remember, and is not said in a derisive tone at all.
 * There's one more reference; in Demons Don't Dream, Dug encounters the grouchy and unpleasant Fairy Nuff, who is annoyed that everyone assumes that, because he's a fairy, he must be gay. Dug solves his problem by telling him to spell his name "FAERIE" instead of "FAIRY".
 * Guilty Pleasure: Oh god yes. The puns, the tropes used, the plots... all combined combined with the Parental Bonus makes re-reading the Xanth novels 10-20 years out of the target audience a very guilty pleasure indeed.
 * That's if it doesn't produce a "I actually liked reading this? What was I thinking?" reaction.
 * Mary Sue: A fair few, but nowhere as bad as the three princesses introduced later - "Rhythm", "Harmony" and "Melody". Whereas characters previously had a limited talent, which was used in a clever way to solve a plot roadblock, the three princesses have the talent to (described in-text) literally "Do Anything" by using their ~ Summonable ~ instruments. Any inventive solutions to plot roadblocks were thrown out the figurative window, as the princesses (who showcase in most books) will solve the problem by themselves with no intervention by the main character of the story.
 * The moons of Ptero also count in a way, as a convenient dumping ground for pun libraries and easy character solutions, due to the presence of "alternate" plot characters and convenient havens for happy, age-inappropriate romances.
 * Nightmare Fuel: What Trent found in Castle Roogna's library in the first book.
 * Pandering to The Base: Xanth is read mostly by hormonal teenagers (of both genders), and Piers Anthony is distinctly aware of this -- and includes a weird combination of fanservice and strong female characters for both sides.
 * Periphery Demographic: Young kids and teenagers, actually, due to a combination of Puns and Fetish Fuel.
 * The Problem With Licensed Games: Averted. The Adventure Game based on one of the novels managed to be at least halfway decent.
 * Except the novel is based off of the game that is based off the novel. It's maddeningly recursive on Your Head Asplode levels. Basically, in the novel, the protagonists are playing the game that is now out, based on the novel, making it a bit of I Wish It Were Real, as well.
 * The Author's Note straightens this out: Anthony wanted to make a Xanth computer game, but lacked the expertise to do it himself. He wrote the novel to show Legend Entertainment what the Xanth game should be like, and they went and made it for him.
 * Running the Asylum, Ascended Fanon: Readers send Piers Anthony enough suggestions in fan mail that Xanth novels now consist almost entirely of such material. Piers Anthony acknowledges these contributions in his chapter-long Author's Note at the end of every book.
 * The way the Dolph/Nada Naga/Electra love triangle was resolved (which hinges on the Exact Words that the Good Magician Humphrey said) was suggested by a fan; in the Author's Note for Isle of View, Piers Anthony said that he hadn't thought of that solution, and had even already written an ending in which the wrong girl "won".
 * Sequelitis: And how. The first book was amazingly original, but by Harpy Thyme the prose is so badly written it can be painful to read in places, among other problems. Many people recommend stopping by Question Quest, and giving the later books a miss except those with characters from the early series (like the aforementioned Harpy Thyme, sadly).
 * Unfortunate Implications: Chameleon's talent is that she shifts from beautiful, but stupid to smart, but ugly, and back, every thirty days. In other words, a monthly cycle... (Which is also the first appearance of the recurring "Smart People Are Insufferable Jerks" theme)