Vorkosigan Saga/YMMV

• Complete Monster:
  • Ges Vorrutyer gets about twenty pages of screen time, and is still a memorable skin-crawler. His creepy obsession with tormenting and torturing his ex-boyfriend Aral takes him from "academically interested in watching a psychologically destroyed Bothari raping Cordelia Naismith on his say-so" to "willing and eager to do the deed himself" in a way that leaves even the normally very calm and balanced Cordelia absolutely terrified. Oh, and guess who broke Bothari in the first place? According to Aral, Ges did it twice: once before Bothari arrived at the Leper Colony, and again after only a few scant months when Bothari was reassigned.
  • Prince Serg was considered Ges' ally and equal in awfulness by those in the know, and was bad enough that his father Emperor Ezar was willing to sacrifice thousands of his own troops and the honour of his best people in an Offing the Offspring Batman Gambit rather than let Serg take the throne. His widow tries to kiss Cordelia's hand in gratitude for her having killed Ges, and later remarks of a suitor that she's had him checked out and he treats his courtesans normally, a point she clearly considers in his favour.
  • Baron Ryoval. Possibly the worst in the series, and given the Complete Monster company he keeps in the Vorkosigan saga, that is really saying something.
    • Baron Ryoval was a legendary figure of horror and revulsion on Jackson's Whole -- a Wretched Hive where things like selling your own children into slavery or murdering a sibling in cold blood for business advantage is considered perfectly civilized behavior. Being the worst guy in the kingdom is one thing. Being the worst guy in Space Mordor is something else again entirely.
  • Commander Cavilo is Miles as a Complete Monster. Miles' friends take great delight in telling Miles this.
  • Mark's foster-"father" Galen is another real prize-winner.
  • Richars Vorrutyer. How he treated his cousin Lady Donna, even when they were children, makes it impossible for anyone to feel the slightest bit of sympathy for him when Miles, Ivan, and the now-trans Lord Dono work in concert to publicly take his ass down.
• Crazy Awesome:
  • Miles at his most manic and inspired arguably slips into this. Perhaps the defining example is the moment where he resolved a hostage situation by threatening to shoot the hostage himself. With a plasma cannon.

Miles had judged the hostage-problem logically insoluble; therefore, clearly the only thing to do was make it Cavilo's problem instead of his own. (from The Vor Game)

• • There's his verbal sparring with Cavilo earlier as well:

Elena: Damn. If I didn't know you, I'd think you were Mad Yuri's understudy. The look on your face . . . am I reading too much into all that innuendo, or did you in fact just connive to assassinate Gregor in one breath, offer to cuckold him in the next, accuse your father of homosexuality, suggest a patricidal plot against him, and league yourself with Cavilo -- what are you going to do for an encore?

• Ensemble Darkhorse: Both "That Idiot" Ivan Vorpatril and Mark Vorkosigan have become intriguing characters due to Hidden Depths, and it doesn't hurt that both love to deflate Miles' ego, and know exactly what buttons to push - Mark even more so since he is Miles. Other popular bit players are Emperor Ezar and Emperor Fletchir Giaja, each of whom only appear in one book (Barrayar and Cetaganda respectively.) Both leave striking impressions of rulers who are cunning and a hint of what Gregor might become when he grows older. Miles is in awe of Fletchir's wisdom, deeming him a Worthy Opponent.
• High Octane Nightmare Fuel / Nausea Fuel: In Diplomatic Immunity, Ker Dubauer's lovely selection of Cetagandan bioweapons will leave you begging for a Mercy Kill before you literally boil into a steaming puddle of melted entrails. Oh, and they leave the brain intact so you're conscious up till the last minute.
• Jerkass Woobie : Ekatrin's first husband. The decay of his marriage is caused by his phyisical difficulties causeing him a low self-esteem and depression that makes him withdraw into himself and neglect his wife. On another planet besides Barrayar he might have been a tolerable husband, but the odd Fantastic Racism slowly got to him.
• Memetic Sex God: Ivan, on Cetaganda, at least. Especially impressive in light of the fact that Ivan's Cetagandan competition has been being genetically engineered toward perfection for centuries. It's probably not just his good looks. And this reputation withstands him being dosed with a drug to ensure The Loins Sleep Tonight.
• Mood Whiplash: "Shopping" is quickly followed by "I paid too much for it".
• Squick:
  • Butter bugs before Ekaterin's cosmetic improvements.

Miles: It looks like a cross between a cockroach, a termite, and a... and a... and a pustule.

• • Cetagandan Kitten Trees. For the love of all that's holy, do not pick one before they're RIPE.
  • The once-human things in Baron Ryoval's research/torture labs.
• What Measure Is a Non-Badass?: Ekaterin comes off as this compared to the rest of Miles's soldier/badass girlfriends, mostly because she's had a quieter, more domestic life. She has a brief Adrenaline Makeover at the end of Komarr that impresses the hell out of Miles, though, so maybe she just has that potential and never used it.
  • Ekaterin acquits herself pretty well toward the end of Diplomatic Immunity while Miles is incapacitated. It's also made clear in the series that there's more than one kind of badassery, and once out from under Tien and in Miles' orbit Ekaterin starts displaying hers, from proposing to Miles in front of the entire Council of Counts to fox Richars Vorrutyer in Civil Campaign to working behind the scenes on both a personal and diplomatic level to make contacting the Cetagandans about the rogue ba easier in Diplomatic Immunity. She's also super-classy towards Miles' various paramours and would-be paramours, even having his old flame Taura stand as second during her wedding.
• Woobie, Destroyer of Worlds: Mark drifts into this territory several times.