Diet Coke.
The Big Bang Theory Season 1, Episode 13
...while Howard threw up
Red Vines and cherry Coke.
The Big Bang Theory Season 4, Episode 20
How hard is 65% Coke,
35% Diet Coke?
The Big Bang Theory Season 12, Episode 23
"Wil, do you want more Diet Coke?
The Big Bang Theory Season 8, Episode 20
Diet Coke, please.
Breaking Bad Season 2, Episode 11