Well, depending, I have mutliple ones.
There's always "Check out THESE guns" when I show my scrawny arms,
"Sorry Mom" when somebody corrects me/makes fun of me,
and during rollcall, instead of saying "Here" I say, "Giving you the great bold flavor since 1945."
But at school, I am also called "Toast" for singing Heywood Banks' Toast song, so I suppose "Yeah, Toast!" would fit in this conversation somehow.