Sideways/Funny

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.
- Then Jack's off-hand (and false) response to the shocked crowd as he guides Miles out: "His, uh, mom just died!"
Miles' attempt to teach Jack how to properly drink a glass of wine. "Are you chewing gum?"
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?
Jack: Oh yeah, new ending VASTLY superior to the old one.

Miles: There is no new ending. Page 750 on is EXACTLY the same.

Jack: (beat) Well...maybe it seemed new because everything leading up to it was so different?

Miles: Yeah, that must be it!

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.