What we know about these two is that they are apex predators in their own respect and people fear Great White's (Carcharodon Carcarias) more than Killer Whale's (Orca). The top speed of both is between 30 and 35 MPH. While Great White's have been on record measuring up to 25 feet or possibly more, most reach between 15 feet and 17 feet. More Orca's, on the other hand, do grow between 25 feet to 32 feet. Interesting to note is the dorsal fin on the 32 foot Orca's is 6.6 feet tall! Now, several years ago two Killer Whale's were observed near San Francisco. Apparently this is rare. Anyway, a Great White came near and one of the Orca's killed it. When the whale resurfaced it had the Great White in its mouth. The Great White was smaller than the whale and it is documented that Killer Whales are the only creature that can kill Great White's. But if a Great White and a Killer Whale, both the same length (say 25 feet long), attacked one another who you think would win the fight? I am in the Great White's corner.
This is the sort of discussion I've frequently had with my two boys aged 9 and 6, and according to my 6 year old's research it is the Orca. Though there is something in me that roots for the great white. And now for a clip confirming Dennis's comment -
I'd have to agree with that, the Great White is just an aggressive dumbass, the Orca is a genuine predator, watch this and its just scary how smart they are:
Same size, I still go for the Great White. Do not underestimate Great White Shark's. They are cautious animals and will attack methodically. A big difference is Great White's are more solitary than Orca's.
Unfortunately, we specialize in destruction, hatred, and extinction of species. These animals do nothing like that. They kill to live, not to make others extinct.