Whenever the skirt is mentioned, especially when it's Kate Bishop, unaware that she's talking to Clint, saying that she never dressed like the first Hawkeye—even when he wore a skirt. Clint's response?
Years later and people still make fun of the skirt...
Hawkeye's reaction to finding out that he and the other Avengers have been transported to a reality that never left the middle ages and is ruled by a powerful sorceress? "Aw man, notanotheralternate universe!"
From his current ongoing series:
Several scattered Daily Bugle papers are titled with the headlines "EVERYTHING AWFUL: Oh God Somebody Do Something!!"
Chris Eliopoulos, the letterer of Vol. 4, keeps putting these in, along with all the Unsound Effect's and other Painting the Medium gags. It's what elevates the title as a whole.
Kate and Clint get into an argument over the labeling and organization of his arrows, or lack there of. She harps on him about this, even during a car chase with gangsters firing at them, causing him to yell at her to pick one at random.
After saving a girl from gangsters and subsequently sleeping with her, the gangsters track them down and starts firing at a still naked Hawkeye. He dodges the gunfire and dives across the room. His Censor Box is a picture of his old mask.
After getting knocked out by the above mentioned gangsters, Hawkeye calls Kate to pick him up. By the time she gets to his location, he's still putting his pants and shirt on. Kate stares at him for several panels, causing him to facepalm.
A gangster holds Clint hostage with Kate aiming her bow at the gangster.
Gangster: You geev me ginger (derogatory patriarchial epithet), I geev you Avenger (slang for male genitalia).
Kate: Wow, the mouth on you.
The Dog Cops subplot/Running Gag in issue 6. Hawkeye watching a show like that? Okay. Spider-Man? Definitely. Wolverine? Freaking hysterical.
Especially since Dog Cops appears to be, literally, a show about dogs who are cops, rather than, say, a K-9 unit; Tony refers to a character named "Sergeant Whiskers" when talking to Clint about it.
Kate talking about how the Roman emperor Domitian could fire 4 arrows at once between his fingers (while Clint is shown shooting only 3 off), then later on Kate fires off 5 arrows at once.
Kate: Suck it, Domitian.
Bit from #6:
Clint: You're going to need more guys.
(A load of guys come out from two vans, who proceed to overwhelm him and knock him out. Page later, Clint wakes up and is unmasked in front of a large room filled with guys)
Clint: Huh, so you got more guys.
Clint insisting to his neighbors that he's not an Avenger...only to be interrupted by SHIELD agents air-dropping onto his roof, hooking him up, and airlifting him into a Helicarrier, all while Clint protests that they have the wrong guy.
Recent issue of Secret Avengers brought us, after being trapped in Earth 666, surrounded by undead Avengers thanks to Captain Britain leaving a powerful artifact in their hands, Clint gets into rant mode, in a way to leave even the most British of readers laughing, followed by classic Clint Barton dialog.
Clint: I hate you Captain Britain. From now on, because of you bringing me here, I will now hate everything about Britain. Tea. The Smiths. The Queen. Brian: Let's leave the Smiths out of this. Clint: God, I hate other dimensions. Way too Doctor Who for me. Feels like fighting fake stuff. Monster!Hawkeye: We're real enough. Brian: Lets test that out the old fashioned way- Clint: -WITH VIOLENCE! ** Later, Clint gets his Ho Yay working:
Brian: Yo think juggling some Avengers is tough work? Try policing the Entire Omniverse!
Clint: Someone feeling underapreciated? I Cherish you, Captain Britian, and you look SO Pretty in that new suit.
Brian: I was worried about using too much black.
Clint: No, its slimming.
Basically, every bit with these two really in the latest arc.
From the second volume of Secret Avengers comes Clint telling Natasha that he and Bobbi can work well together and their relationship is behind them, only for Natasha to be revealed to be Bobbi using camotech.
Even better—Clint's reaction strongly suggests that this isn't the first time he's fallen for Bobbi wearing the camotech and pretending to be someone else.
The solicit for Hawkeye (Vol.4) #15 includes the line, "Plus…two free staples!"
One story arc begins with various mythical creatures appearing all over the world, attacking all Avengers. We only see short snippets of each fight, and this is (paraphrased) how it goes for Clint...
Minotaur-looking creature: You will DIE by the horns of MUTAURUS!
Clint: See, I have this thing about not getting killed by people with INCREDIBLY STUPID NAMES!