Dragon Ball Z, Season 3

Frieza:
I really hate to break this to you, but I've been holding back the lion share of my power for the sake of amusement, but now I'm going to end this fight. But before I do, I'd like to make you an offer.

Goku:
I'm listening.

Frieza:
Join me. You have so much potential, it would be a pity to see it snuffed out and gone to waste. What 'dya say?

Goku:
I can't do it. Sorry. See, I have this nasty habit of following my heart.

Frieza:
Hm...and what does that get you? With me, you would live like a God. Yes, you could have anything. Or not, you could choose to suffer and die. Your call.

Goku:
No way. I have everything that a man could want.

Frieza:
Oh my. You are so naive. You know nothing of the pleasures of this universe. Any desire that you have could be instantly fulfilled. But have it your way. Die if you must. But allow me to let you in on a little secret.

Goku:
Huh? What's that?

Frieza:
Well, I haven't even begun to use my real power yet.

Goku:
Yeah well I have some reserved myself.

Frieza:
Yes, I know. Five. Five times what you've displayed, ten at the very most. But I...I've only used one percent of my power.

Goku:
Huh? What? Uh...no way! You're bluffing. It's just not possible.

Frieza:
Don't be glum. You should actually be flattered. I've never had to summon this much of my power to defeat someone. Fifty percent of my maximum. That's all that's required for this.