"So what?" still strikes me as a perfectly serviceable comeback*. I think of it as the workhorse of comebacks--it may not have mastered the dance moves of a Lippizzaner or have the lightning speed of a thoroughbred, but it pulls its weight when there's work to be done.
*Granted, it's no "So's your face!"
"Chicken in the Car-The Car, She Go"
21 hours ago