I would have to say that Sayid is one of my favs, although Hurley would be a close second to him. I like the "balance" of Sayid: strong - yes, heroic, and with a sense of humour which has sharp edge of sarcasm with it.
I had forgot (since watching it the first time in the States last year) about those lovely dry comments from Charlie in last night's episode on Channel 4. They made me laugh. Loved the whole, "Ok, if you two are finished verbally copulating, can we go then?"