From what I've seen, I'd say the grown up Trunks is pretty cool.
You're right. He is cool, isn't he?
Hmph. Not that cool.
What did you say!? How dare you say something like that about my son?
Gee whiz Bulma, do you think you could freak out any more!?
What!? [holding baby Trunks] Well, we'll just tell daddy about him!
No don't! Not Vegeta! Please, I take it back!
Ha ha. Watch out Yajirobe. Little Trunks is goin' ta be pretty tough himself one o' these days. He may come after you if he hears you were givin' his mom a hard time.
Yeah, I'd like ta see him try!
Ooo! That does it! I'm going to tell Vegeta exactly how mean you're being to his son!
No, you can't tell! I'll do anything!
Oh man! It's freezing up here!
I know. But this is no time to complain.
Just one more reason I'm glad I'm not an Earthling.
[after pounding Krillin to the ground] Heh heh heh. Silly human. What exactly did you think would happen when you found me?
Why don't I show you.
Little fool. You still do not understand!
I see that you have chosen to become an android...
Yes. Now I have eternal life like you. But we have pressing matters at hand. In the past, the two of you have displayed an unacceptable tendency to disobey my orders. I blame myself for this and the way I programmed you. I have since modified your programming however and I will no longer tolerate insubordination.
These quotes come from Wikiquote's Dragon Ball Z pages and are available under the Creative Commons Attribution-ShareAlike License.