"Alright dad, I'm 20 years old now so let me explain something to you. If you so much as think about telling me to be in bed at 10pm with the light off, if I have to ask you for permission to use my own computer, if I have to get your permission just so I can attend a reunion - you know, like the one you wouldn't let me go to over a year after high school ended simply because there would be girls coming, girls I finished school with - I'll take your head and smash it into the corner of your computer desk, and then I'll cut you all over the place."
"Before you continue flailing that tongue of yours, wench, I should point out I'm not against hitting girls."
"Shut the hell up or I'll cut you." (simple)
"First, I'm going to cut your face off. Then, I'm going to sew it onto your ass, so I get to kick you in the ass and I get to kick you in the face, all at the same time!"
"Touch me again and I'll make sure you vomit more than just food and stomach acid."
"Oh boy, you're going to make an excellent addition to the footpath we're standing on!

"
"What a sweet day. The grass we're standing on needs something to drink."
ALT: "What a sweet day. The grass we're standing on needs watering."
"Y'know, when you hit on my 15 year old female friends, you risk losing the appendage you intend to abuse."
(if he's hitting on her again) "Y'know, I feel I was a bit too harsh on you the last time we met. So, I've come up with a new plan. Rather than ripping your meat straight off and sewing it to your face like an elephant, I'm going to use this here box cutter to make your whole crotch vestigial instead."
And now something from Duke Nukem 3D:
"I'll rip your head off and shit down your neck!"