Readers may differ in their response to this question, but I believe that Nick is right. And I believe that Fitzgerald leads us to accept this conclusion. Gatsby is a flawed character. He obtained his money through illegal or at least shady deals. He associated with people such as Wolfshiem who was responsible for throwing the World Series. He engages in adultery with Daisy. He is a socially awkward hopeless romantic.
Yet, the fact that he is willing to take the blame for Daisy's hit and run accident that resulted in Myrtle's death and that he is willing to stand watch just in case Tom reacted violently toward Daisy puts him a cut above the rest. He is not as selfish as either of the Buchanans who seem to do nothing unless it is in their self interest as well as Jordan who cheats at golf and lives off the generosity of others. Yes, I would put Gatsby above the rest. But that is not saying much.