Pembleton and the unmarked squad cars. In the pilot, he forgets to write down the number of the one he checks out, and gets down to the garage only to be reminded that they all look exactly alike. His pride won't let him go back upstairs, so he starts checking the door locks of each.
Later, he's trying to get out of a parallel park job, but the cars in front and behind are too close. Bayliss is preoccupied with Crosetti's funeral arrangements while Pembleton, backing up, pulling forward, backing up, pulling forward, starts yelling "You can get it in, but you can't get it out!" and "I'm gonna shoot this car!"
The music montage in the movie with a frantic Mike Giardello uselessly running around and beating up suspects while Kellerman chooses to ignore him completely and to have lunch.
Pretty much anything John Munch says though his "Montel Williams" rant is definitely up there.
The detectives reading you your rights in "The Documentary".
Howard quitting Smoking and Felton's overreaction to it, and Bayliss getting Pembleton to smoke.
Munch ruining Bolander's and Howard's double date.
Lewis: You're like a father figure to me, big man.
Bolander: You ever repeat that, I'll gut you.
The "Electrolite Neutron Magnetic Scan Test" definitely counts.
Howard twitting Pembleton about her reasons for stopping smoking in "Smoke Gets In Your Eyes". Ed Danvers the "Alpha male", indeed.