"I’m going to tie him up. That’s all, I swear.’"
Remus Lupin - POA (let's face it we've all used that line before)

"Can we have another go?"
Harry Potter 
"Not now. You’ve had enough for one night."
Remus Lupin - POA

“Something silver white, something enormous erupted from the end of his wand.” 
POA (enormous really?)

“But whether James really did take off Snape’s pants, Harry never found out.” 
OOTP (i am personally extremely glad he did not find out)

“Harry was to be found, yet again, kneeling on the floor of Snape’s office.” 
OOTP

"We’re not fussy where we stick this."
Fred Weasley - OOTP (i have an idea)

“Harry’s heart began to pump very fast indeed. Defense against external penetration?” 
OOTP

"Was it… was it you-know-what, darling? Did he use his- thing?"
OOTP (i sure hope he did)

“Harry tried every variation of ‘I need to see what Draco Malfoy is doing inside you’ that he could think off…” 
HBP

"Maybe it’s better when you do it yourself. I didn’t enjoy it much when Dumbledore took me along for a ride." 
Harry Potter - HBP (was he a bit rough hazza?)