The noiseless sight of Paul Giamatti being chased by a fully naked M.C. Gainey.
Jack's attempt to crash Miles' car on purpose by lining it up with a tree, putting a brick on the pedal, and then putting it in drive. Hilarity Ensues.
What Miles resorts to when he needs a drink and the winery bartender will not fill his glass beyond the sample: the spit bucket.
Then Jack's off-hand (and false) response to the shocked crowd as he guides Miles out: "His, uh, mom just died!"
On that note, Frass Canyon as a whole. "Frass" means "insect feces", yet the place is absolutely gorgeous and there's a suitable amount of Scenery Porn. There's even a wine fountain. And the employees there are snobs. Perfect irony.
Miles' attempt to teach Jack how to properly drink a glass of wine. "Are you chewing gum?"
His knowledge of wines likewise, and some of the descriptions he uses. ("Very flabby", "Pinot is a very thin skinned grape...", "Quaffable, but far from transcendent!")
Miles' Oh, Crap expression after realizing he's spilled the beans about Jack getting married.
Miles's mom's...affection for Jack.
Pretty much any of Miles's snarkery:
Jack: That's gonna be my best man gift to you, I'm gonna get you laid.
Miles: (sarcastically) Wonderful.
Jack: I'm not gonna get you a gift certificate or a pen knife or any of that other horse shit.
Miles: I'd rather have a knife.
Miles catching Jack's lie about reading his new draft.
Miles: What about the new ending, did you like that?
Paul Giamatti and Thomas Haden Church discussing the latter's naked backside on the commentary. Giamatti calls it "Two Glad bags full of ricotta cheese," Haden Church calls it "dueling pillowcases filled with milk." The rest of the commentary is filled with similarly colorful metaphors.
On the Easter Egg gag reel for the DVD, there's a sequence where they're filming a naked MC Gainey chasing Paul Giamatti, only for Gainey to collide with the car so hard that he shatters the side window. Because of Gainey's height and the small car being used, he virtually shattered the window with the force of his junk, something Giamatti and Thomas Haden Church take great delight in recalling for the DVD commentary.
Miles having enough of Jack's banter on the golf course, while Jack remains unfazed.
Miles: Shut up, shut up, SHUT UP! JESUS CHRIST, WHAT THE HELL IS WRONG WITH YOU, WOULD YOU PLEASE JUST SHUT UP?! FUCK!
Jack:....What's with all the hostility, man?
Miles also being a pretty terrible golf shot in general
When the angry golfers drive their cart down to confront Miles and Jack, Jack immediately grabs a club and begins to run at the golf cart; the golfers immediately 180 the cart and drive away with Jack literally roaring at them.
The borderline memetic line: "If anyone orders Merlot, I'm leaving; I am NOT drinking any FUCKING Merlot!" is funny enough but Paul Giamatti's reading of it makes it absolutely hilarious.
When Jack asks if he brought his meds, Miles shows it to him by shaking the bottle like a maraca.
Miles's perpetual state of mind perfectly summed up with the title of his book:
Maya: What's it called?
Miles: The Day After Yesterday
Maya: Oh...you mean, 'today'?
Miles: (beat of realization)
When Miles hears his ex-wife is re-married, he immediately has a child-like tantrum of petulance, getting back into the car and declaring, "I'd like to go home now!" When he learns Jack knew for weeks she remarried, he then grabs a bottle of wine and starts to swig it while running down a steep hill, with Jack in pursuit in one of the most awkward and brief chase scenes you will see.