Sam & Max: Freelance Police: Sam often says to Max "You crack me up, little buddy." This is changed around a lot though, usually changing parts with "You bust me up, little pal.", though in a western themed strip it became "You crack me up, ya mangy yella tailed varmint."
Also: "Where do you keep that (Noun), Max?" "None of your damn business."
Sam's "Can't think of a reason not to..." after Max asks to bust up the place.
"With great power comes great responsibility", That's the catchphrase of old Uncle Ben, If you missed it don't worry they'll say the line, Again and again and again - Weird Al Yankovic, "Ode to a Superhero"
During his second stint as the Green Goblin, Harry Osborne had the catchphrase "Gotcha!", used when Spidey realised he was behind a given plot (Harry's main motivation in this period being simply to mess with Peter's head).
Not really official, but he has used the phrase "it's web-slingin' time" more than once.
On one occasion, as his smarter and more-amoral "Joe Fixit" persona:
"Rest assured, gentlemen—Hulk will smash."
The Thing of Fantastic Four has two: "It's clobberin' time" and "wotta revoltin' development".
And referring to himself as "the ever-lovin' blue-eyed Thing" and "the idol o' millions."
Then there's his oft-mentioned "sweet Aunt Petunia" (no connection to the other, considerably un-sweet Aunt Petunia). She eventually appeared in person, and in defiance of expecations it turns out she's an attractive young woman. Presumably there's some big age-gaps in the Grimm family...
Actually, it's established that Petunia was Ben's aunt by marriage, and that her husband, Ben's uncle, was several years older.
In Grant Morrison stories his catch ... noise is "-hh-". This sigh can represent impatience with his allies' methods, irritation that they're second-guessing him or trying to get him to socialise, or even grudging respect. He also uses it where other people might laugh. Similarly, Damian Wayne has "-tt-", usually directed at Dick Grayson.
Transmetropolitan "I hate it here" is one of Spider Jerusalem's more printable ones. Mitchell Royce has "Where's my fucking column?"
The Green Lantern mythos has these coming out the wazoo. There's nine different Lantern Corps, each with their own Oath (Though Orange and White haven't had theirs revealed and Indigo's is gibberrish).
The unofficial catchphrase of the Blue Lantern Corps is "All will be well", following the example of their leader, Saint Walker.
Likewise, the unofficial Orange Lantern catchphrase is "Mine".
Whenever a new Lantern is selected the rings have their own little catchphrase: "[New Lantern] of [Native Planet], [reference to their capacity to engender the emotion the Corps is based on]. Welcome to the [Color] Lantern Corps."
Hal Jordan of Earth, you have the ability to overcome great fear. Welcome to the Green Lantern Corps
Tintin's Captain Haddock: "Billions of (blue) blistering barnacles!" and "(Thousands of) thundering typhoons!"
Astérix's Obelix: "These Romans are crazy! (Ils sont fou ces romains!)", frequently adjusted to complain about whichever nationality is being parodied in this particular issue. (Oddly, this phrase is spoken by Asterix on the inside cover of the French hardbound editions).
Jack Point from The Simping Detective has one that comes in two parts. There would always be one person in ever story would end up asking Jack, "What's your point?" to which he'd always respond, "Comes right after the 'Jack.'" After this, something totally awesome would always end up happening.
Wonder Woman, in the old days, would say "Suffering Sappho!" This was writer Charles Moulton's tongue-in-cheek Take That to Moral Guardians who claimed she was secretly a lesbian. Nowadays she is more likely to say "Great Hera!"
Nexus would occasionally say, "This calls for hyper-speed!" The first time he said it, the comic's letters page had readers complaining it was corny, and Mike Baron had to point out it was supposed to be a joke.
Mezz and his band frequently said "Vootie!" and "Klacktoveedesteen".
His sometime associate Misty Knight, in her position as the current coordinator of the Heroes for Hire, now has "Hello, hero. This is Control. Are you for hire?" This has already seen a number of variations in the still-new series, usually courtesy of Paladin. "Answer me this, hero: are you for hire?"