It's got to be T-Rex... if only for the scene in JP2 where it's drinking from the swimming pool, and smashing through the gas station.... and the obvious cock-up with the boat carrying it... just where was it when the boat crashed?
The "Velociraptors" in JP aren't. Real Velociraptors were about the size of a peacock. They'd only be dangerous to an adult human if they really were pack hunters. More than likely, they hunted our distant ancestors, Morganucodons & Sinoconodons, which were about the size of rats and mice. What we see in the movie are Utahraptors. Except, real U-rapts were almost certainly covered in feathers. T-Rex was almost certainly feathered too. But the rexy still gets my vote.
Galli-MY-mus!
Dinos can swim!