According to Johns' run it'd be Hal. But there's dissention amongst fans of course.
Personally Hal was never relatable for me. But many of the Earth Lanterns can feel dull or douchey. I think I like Kyle the most. He's just very relatable IMO. And I especially love him in what I've read of Morrison's JLA. Just the ultimate team player and a character searching for the feeling of belonging amongst his colleagues. And as he's proved time and time again, Kyle is definitely worthy and capable of hanging with the big guys. His humble self-doubt makes him instantly recognizable and relatable. His humanity is something I can see in myself. Hal, on the otherhand, never displayed much ethos IMO. The others a bit more, but not so much either. I just don't find Hal likable most times.
And as for Alan Scott, I don't know enough about him.