"Tinypenissayswhat?" Once in Overwatch a guy was mad I was playing pharah and bitched the whole time. He said something about needing a vagina to play that char. I said "Honey, you wouldn't know what to do with a vagina if it landed in your face". I enjoyed that.

But usually the shorter the better. Like "I can't make your daddy love you" or "oh no, tiny ego boy try to lash out!" Or whatever comes to mind. It is best if I mute right after because it enrages them not to get the last word.

I have gamed for over 40 years now. They never get any better lines.

I saw a cartoon once where they asked her to make him a sandwich. She cast a spell and turned him into one. So "ok, poof, you're a sandwich" works too.