Humans have differences in using thought in more complex ways, organising in more complex ways. And because of that we can manipulate the world to make tools, agriculture and such.(this allows us to live nearly everywhere of the land in the world.) Humans also have more complex forms of art.
Mind you, though, i think some animals have versions of the above.

Meh, many of the arguments are based either what we perceive, or on how we delude ourselves. Like humans are the only ones that love? How the hell do you know that?? Rational thought? Thought animals never think? They do try the back door if the front door is closed you know. I am sure some will post delusions on how horrible humans are, and that the animals are sooo innocent.