Alternative Character Interpretation: Whether Buffalo Bill is a psychopath, an emotionally-disturbed survivor of trauma, or somewhere between the two. While he's perfectly willing to abduct and kill women to make his skin suit, we're shown that he feels conflicted and remorseful. In particular, when Catherine is pleading for her life and begging to see her mother, Bill is shown struggling to hold back tears. Rather than glorifying in the suffering of his victims, he has to work hard to distance himself from them, avoiding eye contact and referring to them as "it", as he would otherwise wouldn't be able to kill them. He's less a sadist than a pragmatist.
Crazy Awesome: Not all the time, but Lecter's escape in Silence of the Lambs runs on this. Disposing of the guards as mentioned above, then getting their backup to carry him out of the prison themselves by wearing his victim's clothes and mutilated face over his own.
Dr. Lecter: * showing Starling a letter* "This is about my crucifixion watch. They won't give me a patent, but they advise me to copyright the face. ... You may have noticed that in most crucifixions the hands point to, say, a quarter to three, or ten till two at the earliest, while the feet are at six. On this watch face, Jesus is on the cross, as you see there, and the arms revolve to indicate the time, just like the arms on the popular Disney watches. The feet remain at six and at the top a small second hand revolves in the halo. What do you think?"
In a bizarrely creepy way, some of Lecter's killings. In particular, the way he strings up the disemboweled guard to look like an angel during his escape in the movie. The books hint that part of the reason Lecter does this is to distract and shock investigators, tripping them up on the horrific details and giving him more time to cover his tracks or otherwise get clear.
Evil is Cool: He may be the villain, but Lecter's so interesting that you're more intrigued than disgusted.
Fanon Discontinuity: Thomas Harris intended to stop the story with Silence, until the publisher told him either he could write more, or they'd get someone else to do it. Naturally, a lot of fans prefer to stop there.
Foe Yay: Hannibal and Clarice. Who could have guessed?
Genius Bonus: Hannibal famously said of one victim that he "ate his liver with some fava beans and a nice Chianti." Liver, fava beans, and wine all contain a substance called tyramine, which can cause a severe reaction in any person taking an MAO inhibitor drug. MAO inhibitors, in turn, are one of the first antidepressants and were a regular part of the drug regimen given to people in insane asylums before safer antidepressants became available. Thus, anyone committed to an insane asylum — such as Hannibal Lecter himself — would have been forbidden from consuming liver, fava beans, or Chianti.
Clarice thinks that Hannibal's crimes are due to some sort of Freudian Excuse; Hannibal tells her that it's foolish thinking and that she's abandoning the concepts of good and evil for behaviorism. Twenty years later, Hannibal Rising, a book detailing Hannibal's origins and motivations, was released, although itís implied he was naturally evil to begin with, and the incidents in the book just showed him how to put it into horrifying use.
Dr. Lecter:Nothing happened to me, Officer Starling. I happened. You can't reduce me to a set of influences.
The FBI using Johns Hopkins as a source for a list of people applying for sex changes. This means the book has several people, including Lecter, talking about "Hopkins."
Les Yay: In a discussion of motivation, Hannibal tells Starling "we start by coveting the things we see every day." Starling repeats this observation to her FBI room-mate Ardelia, and they smile at each other.
"Would you fuck me? I'd fuck me. I'd fuck me hard."
Mind Game Ship: The interactions that Clarice have with Hannibal himself seems to trick the audience into thinking that they will fall in love with each other.
To be fair in the books, they do.
Nausea Fuel: Plenty. Buffalo Bill's bathtub is a good example.
The rotting corpse in the funeral home
Buffalo Bill's woman suit, seen briefly in one shot.. This is made even more repulsive if you think about Ed Gein, on whom the Bill character is based. He wanted to make a woman suit so he could crawl inside his mother!
Never Live It Down: "Goodbye Horses" by Q Lazzarus. It's a great song performed in Lazarrus' signature contralto voice and filled with rich Hindu symbolism about transcendence. You'll only ever hear people talk about it in relation to the infamous Buffalo Bill dance sequence though.
Nightmare Fuel: Plenty. Especially the scene with Catherine in the pit where she sees the broken fingernail.
The Woobie: Averted by Catherine, who defies Gumb at every opportunity, and is depicted less as helpless than simply overpowered. She's almost an Action Girl, and despite using Gumb's beloved poodle as a hostage against him, she quietly whispers to the dog that she'd never hurt it. She even keeps the dog in the end of the movie taking it with her into the ambulance. (How much of an aversion this is can be contested, though, as she's pretty clearly traumatized for life after all of this.)
Clarice, for all her power and intelligence, has shades of this when she breaks down crying in her car, and in stories of her childhood.