Nick: intelligent, naive, observant, pure, discreet
Daisy: vain, shallow, passionate, insensitive, selfish
Jordan: straightforward, smart, experienced, fun-loving, accepting
Tom: determined, brave, aggressive, deceitful, unfaithful
Gatsby: ambitious, naive, honest, pure-hearted, intense
Nick is new to the vanity of society, its shallowness and selfishness. He believes people to be good and he is discreet, not discussing other people's affairs.
Daisy, on the other hand, is skilled in the art of social climbing. She and her friend Jordan accept reality and society as they are and know how to make the best out of situations. Daisy only thinks of herself and what is best for her and her lifestyle. Jordan is a smart woman, but she has chosen fun over love, a superficial reality over profound dreams.
Tom and Gatsby are opposites. The former is a brute born rich. The latter is a gentleman born poor. Tom, just like his wife, Daisy, understands how the world works and how to make the best out of it. He's used to having anything he wants and knows how to keep the upper hand. Gatsby, though, is ambitious but innocent. Even though he is a criminal, he's inherently good and, just like Nick, believes there is goodness in everyone. That is precisely his mistake. He idolizes Daisy, failing to see her ugly selfish heart.