Scott Adams is very fond of using playing with this trope in Dilbert, perhaps more so than in most series. He takes it to both logical ends by showing the workers suffering when the secretary replaces their regular supply with decaf, as well as his titler character gaining Psychic Powers when given an unlimited supply of coffee. Wally is the most extreme example. When Catbert and the boss order him to cut down to 40 cups a day, Wally screams "Not Double Digits!". The strip that best illustrates the Pointy-Haired Boss' evil? The one where he finishes the coffee without refilling the pot.
Played straight in Adam@Home.
Garfield strips, especially later ones, sometimes use coffee-addiction gags. A funny variation is when Jon was sitting calmly, while all of a sudden a clearly unhinged Garfield slamms a mug on the table and screams "BEAN ME!"
And there's also a little flash "game" on the official site where you can feed Garfield coffee and watch him wake up and become more and more unhinged. It's aptly named Bean Me!
A Running Gag in the comic involves the father of the Fox household being rather non-functional, sometimes to the point of Cloudcuckoolander-ness, without his morning coffee.
Another comic has Peter weaning himself off of coffee, remarking that he drank so much during finals, if he went cold turkey, he'd die. When asked if he was drinking half-decaf, half-regular, he remarked "quintuple espresso".
Another of Peter's stay awake at all costs brews is coffetea (tea brewed with coffee), which is apparently just this side of a controlled substance.
In one arc, Paige uses coffee-tea in quantities that shock even her brother, which is quite a feat.
Speaking of Roger, on one occasion he was so out of it that he tried to pour his coffee into an upside-down mug. When Paige helpfully pointed out his mistake, he flipped both mug and coffeepot.
Paige herself is rather inept at the concepts involved in the culinary arts, even to such a degree that she uses a cup of grounds to a teaspoon of water. I'll give it one thing, it wakes her folks up.
"The pot's over by the fridge... The fridge is over there... See that thing with the blinking red light?... Roger, that's the answering machine." The last line said as we hear slurping sounds from off-panel.
In one strip, Peter comments that you know you've made coffee right when it's the fumes that wake you up.
In another strip, Peter drinks a whole pot of coffee to give him an edge in math test he's dreading. In the last panel, he's trying to take the test, but sweating, red in the face, and thinking, "If the boy's bathroom is one-thousand feet away and I run at a rate of a hundred feet per second..."
At one point, Roger goes in for a physical. When the doctor asks how much coffee he drinks in the morning and he replies "a coupla things of coffee." The doctor says "Two cups of coffee is OK. What else?" "Pots, not Cups."
One of Peter's bright ideas to stay up long enough to finish a book report was to mix an entire jar of coffee crystals with hot water and drink it all at once.
Subverted in one Bloom County strip, with vice-presidential candidate Opus stumbling around in a morning stupor, mumbling about needing coffee. Then he reads a newspaper. BOING! "Who needs coffee when you've got the latest poll results?"
Phoebe from Zits, who list "caffeine" as her religion when she applies for a job at Fourbucks Coffee. And has an espresso machine in her locker.
