Bug, of Micronauts, Annihilation: Conquest and —*Tik!*— Guardians of the Galaxy takes this to its logical extremes, as his tic is that his speech is randomly interrupted by "TIK", a side effect of his speaking difficulties.
Blindfold of X-Men is... hard to describe. As she's having a conversation with you, she sounds like she's giving yes-or-no answers to someone just offscreen.
Similarly, several Marvel monsters as seen in Nick Fury's Howling Commandos, including the Glob (who needs a special respirating device to speak and breathes with a deep "-SSSK-" a few times a sentence) and the Zombie, whose limited intelligence keeps him from completing a thought without stumbling through it with several uses of "Um..."
And following that pattern, as The DCU's Metal Men began to develop more distinct and expressive personalities, Dumb Muscle Lead couldn't complete a thought without interrupting it with "Uhh..." Tin's stammering may also count, and Mercury boasts about the fact that he's the only metal that's liquid at room temperature so often it might as well be one of these, too.
Batman villain Scarface has a slight variation in that he pronounces the letter "B" as "G" (because the Ventriloquist is the one actually talking and this is an actual problem faced by many ventriloquists); Humorously, this means, among other things, that he cannot properly say "Batman" or, indeed, speak intelligibly at all depending on the context. When Peyton Riley became the new Ventriloquist, Scarface's "B" sounds became actual "B" sounds.
In a straighter example that ties into this, Scarface often ends sentences with "guddy goy."
This became a major plot point during the Cataclysm story arc - Robin revealed the Quakemaster to actually be another of the Ventriloquist's puppets by daring him to say his name, since he had been carefully avoiding words with B in them. Unfortunately, in his first appearance, Quakemaster correctly pronounces the word "Burn".
Oyuki-chan, or as Ninjette calls her in reference to her verbal tic, "fucking Oyuki-chan".
Grant Morrison gave unique pseudo-tic catch phrases to several characters in his JLA run (most of them were Gotham-based) including Batman: "hh", Huntress: "tt", and Commissioner Gordon: "ff". He even uses Damian Wayne's "tff" and "tt" as subtle cues that he really is Bruce's son.
In the Morrison-penned Final Crisis, "hh" is Batman's dying word.
Wingman, the member of the Club of Heroes who spent his whole life trying to be Batman and thus emulates him even in this sense: he uses "tt", and his own dying word is "kk".
In ABC Warriors, Happy Shrapnel, as one of the oldest ABC Warriors still in service, is often interrupted during speech by an uncontrollable buzzing sound that sometimes conveniently takes the place of expletives.
Though this isn't without purpose, as it would otherwise often be impossible to know that he was indeed in the scene; especially when he's doing espionage.
Nova introduced an alien Corpsman who abuses the prefix "ultra-".
Worldbreaker in Atavar begins the majority of their sentences with "We are Worldbreaker."
BIONICLE's air characters have a habit of running pairs of words together, often redundantly ("Toa-heroes" has come up more than once). There are exceptions, since this is apparently a slang that's only common in Metru Nui.
When nervous, Chrysoprasia from DR And Quinch is "unbelievably quiet apart from the weird, squeaky little 'EE-OUK' noise that she keeps making in her throat."
In Judo Girl, master villain Captain Steel succeeds in transferring his consciousness into a sentient liquid form, which for some reason causes him to repeat the last syllable in every sentence he speaks. For example: "My body is my intelligencegencegence. I am invulnerablebleble. I am immortaltaltal. At last, I am truly Captain Steelsteelsteel!"
The Messiah in Preacher frequently uses the nonsense word "Humperdidoo", or some variant thereof.
Jaeger Ayers of Finder tends to refer to the people he's talking to as 'cousin' quite a lot.
Mary Jane has a tendency to refer to people (especially Peter but he's not the only one) as "Tiger" (or in Gwen's case "Tigeress").
Hawkeye's 2012 ongoing series features Russian gangsters who say "bro" at the end of every sentence — and sometimes at the beginning, too. Their boss has clearly tamed this compulsion somewhat, with only most of his sentences ending in "bro".