John Constantine is generally fairly vulgar (in a British manner), but Brian Azzarello's run on Hellblazer took it to new heights: One issue had the "F-word" appearing 51 and a half times in a single issue, prompting the then-Director of Production to ask the Publisher, "Is this really necessary?" (For those who care, the one-half was someone screaming, across the top of a panel, "FUUUUUUUUU".)
Averted by editors, and subverted by Neil Gaiman: John Constantine was apparently supposed to drop the F-bomb about 6 times, but editorial objected—the result was "felching heck", which isn't much better in the end.
Transmetropolitan. Both displayed and referenced. For example, aside from the cuss-laden dialogue, the reader is informed that after the Beast won the last election, Spider Jerusalem attempted to submit an "8,000-word" column of the word "fuck" written 8,000 times.
Sam & Twitch, a spin off series of Spawn during the late 1990s had every single page of every single issue absolutely brimming with profanity. There was some fanmail at the back of each issue praising the writers for not swearing just to try to be cool, though I'm sure they were just trying to be ironic.
The Cluster F Bomb is dropped in a lot of Bendis's work. The first word in his Marvel series Alias is "Fuck!" and it really sets the fucking tone for the entire fucking series, fuckfaces. This is how the fuck Bendis talks in real fucking life. That fuck says fuck all the fucking time.
In an interview regarding his run on Alias, Bendis himself admitted that he may have overused the amount of F bombs in the comic. And subsequently cut down on the amount of swearing for the remainder of the series.
In the last (so far) book of Górsky & Butch, they do a Matrix parody. When they appear in a "blank page", Gorsky launches into a Cluster F-Bomb to prove that they are outside the "comix" and no longer bound by its rules.
In the Nodwick story Krutz, two necromancers need a word of power ("krutz") said more times than they can hope to themselves in any reasonable amount of time. What do they do? Make it a swearword and popularize it overnight.
Empowered: Oyuki a.k.a. "████ing Oyuki-chan", every few ████ing words—hence her ████ing nickname.
This was Moon Knight's response when he knew that Spider-man was unmasking in Civil War. It was bleeped out of course but he swore for about three panels.
In Rat Queens, every major character has a foul mouth and very little inhibition about using it. Hannah in particular, especially when she's dealing with Tizzie.
The Boys: Has plenty of swearing of course but from the Homelander after The Reveal "YOU FUCKING FUCKING FUCK. YOU FUCKED MY LIFE!"
Preacher much like The Boys is another one of Garth Ennis' works and every bit as profane. To quote Sheriff Root.
Sheriff Root: SON OF A FUCKING WHORE WHAT THE FUCK IS GOIN' ON FUCK THIS FUCK
This trope can apply to pretty much all of Garth Ennis' adult oriented work. As he appears to be incapable of writing a sentence without including at least one F Bomb. Regardless of whether or not it makes sense in context.
His work on The Punisher MAX takes this to ridiculous extremes. The gratuitous nature of the dialog feels like it averages at least 30 fucks per issue. With one character dropping over a dozen fucks in a single panel alone. At times the crudeness of the vulgarities veers into the realm of self parody. Take this excerpt from one story arc:
Russian Thug: FUCKING COCKSUCKER. Fucking faggot, fucking pig shit, get up and fuck with me some more.
Zodon of PS238, though due to an implanted chip he says random words instead of actually swearing; long torrents of cursing are transliterated as show tunes.
One issue of Cerebus the Aardvark consisted primarily of a secondary character sitting in a chair swearing.
Negan, from the The Walking Dead. It's easier to count the times he DIDN'T swear.
Monstress has this from Border Warden of Pontus when telling off the Blood Queens for trying to forcibly cross the border.
You are in violation of the First Treaty of Fair Waters, Stipulation 5, Section 2. Specifically, and I quote: "Do not cross the fucking border without the fucking permission of the fucking Pontus government." Which you do not fucking have.