A Christmas Carol: Averted; a case of Beam Me Up, Scotty! and Memetic Mutation has resulted in "bah, humbug!" becoming the Catchphrase of Ebenezer Scrooge. "Bah, humbug" is only spoken twice in the novel, though "humbug" comes up a few more times by itself. At that time, "humbug" meant "hoax" or "jest", so Scrooge was just dismissing Christmas as a fraud in the lingo of the day.
Shagga, son of Dolf: I will chop off your manhood and feed it to the goats.
Patchface: I know, I know, oh oh.
Reek: You have to know your name.
The Dothraki in general: It is known.
The Braavosi in general Just so.
Jaime Lannister (internal dialogue) She's been fucking Lancel, Osmund Kettleback and Moon Boy for all I know...
Asha Greyjoy:(hefts her axe) "This is my husband—" (draws her dagger) "—and this is my suckling babe!"
Herman Melville's "Bartleby, the Scrivener" practically never says anything other than "I would prefer not to."
Garion's catchphrase in David Eddings's The Belgariad, which the other characters quickly become tired of, is "Why me?" Eventually answered as "Would you have trusted anyone else to do it?", but not before various other characters have taken it up briefly. In one scene Belgarath (who's The Obi-Wan, and usually the one being asked and not answering), says it, much to everyone's amusement.
Silk's is "Trust Me" (which you actually shouldn't) and Errand receives his name because for a while "Errand" is the only word he can say.
Gurgi mentioned "munchings and crunchings" often enough for them to count as a catchphrase; also his 'Poor Tender Head'.
Fflewdur Fflam used "Great Belin!" as his trademark Unusual Euphemism (Belin is an ancient Welsh sun god),
Princess Eilonwy would often cry "Taran of Caer Dallben, I'm not speaking to you!" or some variation of the same. She also has a habit of talking in similes and metaphors. For example, "It's silly to worry because you can't do something you simply can't do. That's worse than trying to make yourself taller by standing on your head," or "I don't like being called 'a girl' and 'this girl' as if I didn't have a name at all. It's like having your head put in a sack."
Ciaphas Cain: "If I had known (X) was going to happen, I would have shot (Y) myself."
Lieutenant Villain Dance has a strong tendency to think or say "Never happen!", as in "it will never", when he considers failing in his duty or being shot down.
Dinotopia: "Breath deep, seek peace" or the Skybax riders' variant. "Breath deep, fly high, seek peace" or simply "Fly high, seek peace".
A handful of Discworld characters have catchphrases:
Bonus points because this one was also uttered, on request, in "Wizard Language".
Granny Weatherwax: "If you ain't got respect, you ain't got a thing," "I can't be havin' with this," "Blessings be upon this house", and of course written, rather than spoken: I ATEN'T DEAD.
Death: There's no justice. There's just me. Which in Mort became There's no justice. There's just us.
In Dan Abnett's Gaunt's Ghosts novels, Beltayn, Gaunt's adjunctant and vox officer, says "Something's awry" to report any kind of problem. Up to and including imminent disaster that could kill them all — a fact Lamp Shaded in the books.
Abnett also uses this with Aemos in Eisenhorn whose favourite phrase is 'Most perturbatory'. It's even his last words.
Scarlett O'Hara of Gone with the Wind fame has "Fiddle-dee-dee!", "Great balls of fire!" and (in the book) "God's nightgown!"
The Harry Potter series has Hermione's catchphrase "I read about it in Hogwarts: A History."
Harry's trademarked "Expelliarmus!" could also count (but also doubles as a Signature Move)
"Bloody hell!" is Ron's catchphrase in the films, but is a Beam Me Up, Scotty! as far as the books go.
Honor Harrington has the phrase 'Let's be about it', which she adopted from her first Captain, and which several of her subordinates have begun using.
In the third book of The Hunger Games, Peeta often asks "Real or not real?" thanks to the Mind Rape he suffers at the hands of the Capitol. Haymitch also calls Katniss "sweetheart", mostly to annoy her.
Into the Darkness, King Swemmel of Unkerlant is inordinately fond of 'efficiency' in all things.
In the Mash novels, Hawkeye has "Finest kind!" as a Catchphrase. This made it to the movie, and appeared in some of the earliest episodes of the TV series, but was eventually forgotten or abandoned. Hawkeye and Duke together share the Catchphrase "We're the Pros from Dover".
In Clint McCullough's Nevada, the main character, Meade Slaughter, when surprised by something, says "I'll be damned" so much that after it's his only response three times in a row, his daughter in law lampshades it: "Meade, if that's your only input, I might as well be talking to the wall."
In the Odd Thomas series, the phrase "The dead don't talk. I don't know why." appears in every book, usually just after Odd has revealed his "gift".
A frequent comment of Mrs. Bird in Michael Bond's Paddington Bear series was "Bears always land on their feet."
The Reynard Cycle : "He/She/They had some skill," is Isengrim's. It usually refers to someone who he's just killed, and is meant as a genuine compliment.
Tiecelin (and his pets): "Doom."
Christopher Moore's Sacré Bleu features The Colorman, who excuses every manner of horrifying acts with the phrase "Accident. Couldn't be helped."
Pseudonymous Bosch's Secret Series (The Name of This Book is Secret and sequels) has Max-Ernest. How 'bout that?
Kilroy 2.0: "Kilroy 2.0 is here. Kilroy 2.0 is everywhere."
Sherlock Holmes's Beam Me Up, Scotty! is: "Elementary, my dear Watson", a line never found in the novel series. Then there's "The game's afoot!" which is actually a Shakespeare quote that Holmes utters once in the original stories. He does, however, have at least one genuine catchphrase: "You know my methods. Apply them!" This phrase or variations on it are used maybe six or seven times in the canon, but it hardly ever shows up in adaptations.
Rumo, a minor character in The 13 ½ Lives of Captain Bluebear, at one point tells the eponymous character that he's not good with words when trying (and failing) to explain a situation. When he becomes the main character in the following book, Rumo & His Miraculous Adventures, "I'm not good with words" has become his catchphrase, said whenever he's asked to explain or elaborate on something.