"Darn tooting, I do.
The Big Bang Theory Season 3, Episode 16
Darn it.
The Big Bang Theory Season 12, Episode 8
Hot DARN!
The Big Bang Theory Season 5, Episode 20
And Heisenberg says,
"Darn it, now I don't know where I am."
The Big Bang Theory Season 10, Episode 21
You're DARN right, you wouldn't.
The Big Bang Theory Season 10, Episode 4