Pointy-Haired Boss: (handing back a paper to Alice) Thanks, hun. Alice: Hon!? YOU SEXIST # @$! I SHALL BURN DOWN YOUR VILLAGE AND MAKE SLAVES OF YOUR CHILDREN! PHB: It's short for 'Attila the Hun'. Everyone calls you that. Alice: That seems a bit harsh.
Also, in yet another Dilbert strip, PHB is reading the newspaper comics section and remarks, "Hee hee! Look at the hair on that guy!" For bonus points, it's implied that he's reading Dilbert itself.
About two-thirds of the punchlines in For Better or for Worse use this, by way of demonstrating how (theoretically) adorably flawed the characters are. Happens a lot to Cathy, too.
In one example, Calvin rants for three panels about people who complain too much. Hobbes replies, "Maybe they're not very self-aware," to which Calvin replies, "Boy, that's another thing that gets on my nerves!"
Another example is when they discuss Calvin's Saturday morning habits. Then Hobbes asks whether Calvin doesn't fear that so much violence (in TV) desensitizes him to which Calvin replies something like, "Nah, I'd like to shoot the idiots who think this stuff affects me."
Yet another, in one strip Calvin relates to Hobbes how his grandfather hates comics these days because they're just talking heads... while their characters don't change a bit the whole strip.
Still another (Watterson loved this gag):
Calvin: You know why birds don't write their memoirs? Because birds don't lead epic lives, that's why! Who'd want to read what a bird does? Nobody, that's who!
Calvin: This is changing the subject, but have you ever noticed how somebody can say something totally loony and not be aware of it? What are you supposed to do, just let it slide??
Hobbes: Sometimes, if you wait, he'll top himself.
Calvin: I say just punch 'im then and there!
There's another incident that twists this trope slightly. Calvin is arguing with his parents about having to sit at the dinner table instead of eating in front of the TV. His father says that this is the one time where all distractions can be put aside and they can just enjoy each other's company...right before the phone rings and the mom leaves to talk. Calvin sort of lampshades this trope by saying, "Go on, Dad. I believe you were saying something funny."
In Garfield, when Garfield watches TV: " Only an idiot would watch a show this bad. (switches channel) It was a rerun anyway."
A similar 1979 strip has Garfield slapping Jon - hard - to force him to change the channel because Garfield doesn't like violence on TV.
In another strip, Garfield kicks Jon. Jon attempts to get his own back by spraying Garfield with a hose, but Garfield appreciated it because it was a hot day. Jon then kicks Garfield back....so Garfield ties Jon up violently with the hose.
One strip has Jon getting into an argument with his failed date and she tells him how immature he's acting. Jon yells back, "I am not immature!"; once she leaves he proceeds to sit back and suck his thumb.
The long-running They'll Do It Every Time was all about lampshading everyday hypocrisy. A typical strip, for example, might show a parent admonishing a child not to speak at the table in the first panel, then show the same parent loudly holding forth among other adults at a dinner party in the second panel.
The Family Circus had one strip with the mum admonishing Billy, "I've told you a million times not to exaggerate."
More than once: A group of officers gathered to judge a breach of the dress code criticise it while wearing an array of pretty random clothes themselves. Also other similar cases. Perhaps more often, it's done the other way around, with three parties, not getting as far as the trope: A tries to complain about B's behaviour X to B's superior C, but it turns out C is doing X himself.
Another one used in several variants: A criticises B for their hobby or obsession or habit, but A returns to his own room/bunk, where he has a similar collection of things/arrangement going on set around another theme. For example, Corporal Yo notes Sergeant Snorkel's huge collection of food-related electronics before returning to his own room full of different electronics. Or Sarge says it's weird of Beetle to collect comics, and then someone else points out his own shelf full of beer cans.
General Halftrack's "Have you gone mad! I'm an airplane!" (He'd been hypnotised.)
In one strip of Baby Blues Hammie meets a kid at the playground who looks just like him except with long hair, both think to themselves "What a weird looking kid!".
One Blondie strip had the family going to a restaurant where the chef juggles the food onto the plates, everyone claps except Dagwood, later Alexander asks him "You didn't like it dad?" and Dagwood replies "Oh pu-leeez, what a show-off!", then when they get home he says "Who wants dessert?" while making sundaes and juggling the ingredients.
The Wizard of Id had a strip where the preacher mentions he doesn't know what to use for his sermon next week. The king suggests the evils of gambling, which the preacher turns down as both hear the cry of "BINGO!" from the church.
A Peanuts strip has Charlie Brown, who's dreading having to go to summer camp, seeing Psychiatrist Lucy about it:
Lucy: This fear of going to camp is something you've got to overcome! It'll be good for you! It'll teach you to stand on your own two feet! This is just the sort of experience you need!
Charlie Brown: How about you? Are you going to camp this summer?
Lucy: AND LEAVE MY GOOD HOME? DON'T BE RIDICULOUS!!!