Simple enough, choose your favorite character, and explain rationally why you feel so attached this particular person.
I'll go first; my favorite character on LOST is John Locke. From his first screen appearances I was intrigued by this character's mysterious persona. Despite the pandemonium surrounding him on the beach, and afflicting the survivors of 815, Locke is totally content, and composed. I awaited his flashback episode intently, and when Walkabout rolled around I was surprised by the impotence of his off island persona. The juxtaposition of his tough hunting islandself and the depressed, paraplegic, and victimized corporate Locke was brilliant, and he revelation of the wheelchair was the vehicle to which I realized I loved the show as a whole. The resounding optimism of his first steps on the island amidst the sight of this horrific crash was wonderful.
Anyway, Locke is a total badass. But he is plagued with self doubt; he cries quite frequently throughout the story. His character is very complex, but his intentions are clear: He seeks a greater purpose, and to him it is the island. Now, Locke is currently dead, and if he remains dead and it turns out his story is over I will have to change my favorite character to Jack, because to me Locke still has work to do. His story can't be over yet. Locke's death is merely a minor set back. I think he still has a more meaningful destiny to fulfill.
I dunno. I've been seeing a lot of favorite character contests here, but those don't satisfy me. I want to see why we like these characters, not just who we like.