TARS is my favorite character in Interstella.

TARS: I have a cue light I can use to show you when I'm joking, if you like.
Cooper: That might help.
TARS: Yeah, you can use it to find your way back to the ship after I blow you out the airlock. [cue light flashes]

Cooper: You'd do this for us?
TARS: Before you get all teary, try to remember that as a robot, I have to do anything you say.
Cooper: Your cue light's broken.
TARS: I'm not joking. *Flashes cue light*

Cooper: Humor, seventy-five percent.
TARS: Confirmed. Self destruct sequence in T minus 10, 9...
Cooper: Let's make that sixty percent.
TARS: Sixty percent, confirmed. Knock knock.
Cooper: You want fifty-five?

Cooper: Hey TARS, what's your honesty parameter?
TARS: 90 percent.
Cooper: 90 percent?
TARS: Absolute honesty isn't always the most diplomatic nor the safest form of communication with emotional beings.
Cooper: Okay, 90 percent it is.