[to himself] What are you thinking, Kakarot? There must be a plan behind all this...this insanity!
I may be giving up, but that doesn't mean the tournament's over. There's still one more person for you to fight.
You're not serious! Who? One of them!? And exactly which one of these pitiful specimens did you have in mind, Goku? Who? Trunks, Piccolo, Vegeta? Please, don't waste my time.
[to himself, about Goku] Disappointing. He promises me a challenge and he gives me nothing but a child!
[to Goku, after Goku tosses a senzu bean to Cell] Okay, it's official! You've completely lost it!
Look, Cell's kind of worn out right now. It just wouldn't be fair if Gohan beats him when he isn't at his best, you know.
That...that's Cell up there! Who really cares about being fair!?
[to himself, about Goku] Heh heh heh heh heh. What a fool. Doesn't he realize...? The only thing he's managed to do here is ensure his son's demise.
[to Gohan] Well, I'll give you this. You certainly are brave. And loyal too. Not many sons are willing to die fighting their father's battles, you know. Your devotion really is most admirable.
These quotes come from Wikiquote's Dragon Ball Z pages and are available under the Creative Commons Attribution-ShareAlike License.