Aha!
The Big Bang Theory Season 7, Episode 3
answer the door or should I
open it and say "AHA" again?
The Big Bang Theory Season 7, Episode 2
Aha! So I am working with you?
The Big Bang Theory Season 3, Episode 4
Aha!
The Big Bang Theory Season 7, Episode 2
A-ha!
The Big Bang Theory Season 9, Episode 13