Goku, Vegeta, and 18, please kill those little shits. Send them to the next dimension, blast them, rip them to pieces. Z Fighters: Yes Sir. *They massacre the brats. Slade watches* Slade: wow. They killed the Titans. Best that I get the hell out of here. *Slades head is blasted open from a bullet. Deathstroke reloads chamber to his rifle.* Me: Here is your fee. Deathstroke: No you keep it. I all I wanted was for this shit of a villian who is supposibly me.
I sorta see Gohan and Videl looking for the dragon balls, running into...say the High Five, transform(Saiyaman costumes) and take em down. The Titans are overlooking them and get along well. Except Starfire who's edgy because of Gohan being a Saiyan. Slade returns, defeats everyone then Goku and Piccolo show up for backup.
Vegeta's in a modified version of his Namek Saga appearance when he should be in his Androids Saga appearance. Android 18's boots are wrong. They should be shorter. Gohan's costume is just all kinds of wrong if you're going for his pre-Hyperbolic Time Chamber/Room of Spirit and Time appearance. His shirt is done incorrectly (the white is on his collar, not his arms), and he should not have a tail. Master Roshi's in an outfit I've never seen before.
It's quite hard to choose from because both sides have high chances on winning. But I think the Titans will win. Sure DBZ have that saiyain mode. But the Titans are skilled heroes. Cyborg is a half-machine, he could be an atomic himself if he ever built one. Starfire is an alien princess/warrior with super strength Beast Boy can shapeshift to any different type of animals, he can even shapeshift into alien forms and demons. Robin was trained by Batman, no need to explain. Raven is a half-demon, whose father is an inter-dimensional demon that ruled and destroyed over 10,000 worlds and not to mention that she can open portals herself. Raven can probably zapped open to another world where the DBZ characters are vulnerable (I don't really watch DBZ, but everyone have weaknesses.)
Sorry if I sounded ignorant, but it is just my opinion. Since this is obviously the cartoon version, the younger fans of the show didn't see full potential of the Titans since Cartoon Network had to keep it PG/G-rated. Bah... -_-