"Everyone thinks I'm a man in real life." (17.27)
Art3mis defies expectations that girls are no good at games and can't be geeks in the end by actually being female.
"No one ever looks anything like their avatar." (17.73)
This line is ironically uttered by Art3mis, the one person who looks the most like her avatar out of all of them. Aside from that one thing, she seems pretty comfortable with herself and her appearance.
"Competition brings out the best in me." (9.113)
Art3mis says this line, but it could really apply to just about anyone in the novel. The competition for Halliday's egg is so heated, it puts the pacing into overdrive. If it weren't for all these highly competitive people, the plot wouldn't move nearly as fast.
"I don't know [if I can save the world]. Maybe not. But I'm gonna give it a shot." (9.141)
Even when something is against all odds, Art3mis gives it a try. She's also talking about the real world—planet Earth—not the OASIS, which is the only world Wade is concerned with.
"If I win [...] I'm going to make sure everyone on this planet has enough to eat. Once we tackle world hunger, then we can figure out how to fix the environment and solve the energy crisis." (9.137)
In a world where people would rather spend money on digital clothing and gas for their spaceships, we're not sure they deserve a savior like Art3mis, but at least her heart is in the right place.
"It's not about the money. It's about what I could do with it." (18.69)
Art3mis's goals are a little more long-sighted than just making bank. She's setting goals beyond that, imagining what she can do with the money to heal the world. Of course, it all depends on her winning the money. What would her goals be if she lost? How would she have handled that monkey wrench?
"You could become famous in the real world too [...] if you reveal your true identity to the media." (9.123)
Being famous in the real world requires tearing down the wall between real-life and online identities, something Wade isn't ready to do at this point in the book, either out of fear or a simple preference for the two to remain separate.