"You have to stop the Q-tip when there's RESISTANCE!" - Chandler Bing, Season 2, Episode 1.
Yeah, look, it's a pretty decent line. But is it the best? Let's investigate.
There was the one where he was absurdly honest about his single status:
There was the one where he couldn't make the ~whip~ sound:
There was the one where he stole Monica's bath:
And who could forget the one where he tried to advertise things:
But the winner has to be, of course, the one where Ross told him to pivot: