The older nerd in me wants to say A. fragillimus, one of the sauropods that only has, like, a leg bone or something that has been founs but, if to scale with other dinos, was like the biggest animal of all time at like 150 short tons and almost 200 feet long. Fuck you, blue whale, just a fat kid in the pool- here comes the real king of the playground!
...
And then people decided that that wasn't accurate or something, and that it was probably still huge, but nowhere near those dimensions, because science is always taking away my monsters.
But the little kid in me will always love the T-rex. I hated King Kong and anything that had a T-rex defeated in the story- I was a real dino nerd when I was young.
The young me hated the then-emerging popularity of the 'closer to birds' theory. But, you know, I got past it (when it was explained that they weren't really all big chickens, but their own distinct animals and that one strain just happened to eventually become what we know as birds. And I was older).