'An interesting character. Not necessarily a likeable one, not even necessarily a relatable one, but an interesting one. The best example of a complex main character in all of science fiction is Robinette Broadhead in Frederik Pohl’s Hugo and Nebula Award-winning Gateway, which is told as flashbacks during Broadhead’s psychoanalytic sessions with a computerized shrink. He’s not at all likeable, but, wow, is he ever fascinating.'
It also applies to player-characters in games. Players can be too worried that others will judge them personally by the characters they choose to play. Screw that. There's nothing more boring than a game populated by decent people, however much we'd like real life to be like that. Make your characters interesting, and never mind if they're nice.
Some more thoughts from me on that here and here. But you're always having to put up with what I think, so if you're pressed for time look at Mr Sawyer's advice. Like Pohl, he too has won the Hugo and Nebula Awards. He says, 'I was born to write for [the Star Trek] franchise!' and I concur. I would love to see his take on the ST universe.