Jack and Hurley are the most important by Cameo

I think that in the end, it will be Jack and Hurley who are the most important characters. I think this because my belief is that MIB has been after them for a long time. Now I haven't re watched any of the seasons for a while so I could be missing instances where this happened with other characters, but these are the only two I could think of.

I think MIB knows that Hurley and Jack are important, so he's tried to take them out before.

I know its be theorized that MIB has manifested himself as Christian before and I believe that too. Remember when Jack was chasing 'Christian' through the woods, as he was chasing him he tripped down a hill and almost fell over a cliff. John helped him back up. MIB manifested as Christian to get Jack to chase him so he would trip, and hopefully fall off of that cliff. I don't think however, he was counting on John being there. (Or maybe even a John from another time flash, but I don't want to get too far in to that.)

Now Hurley. Well, to continue my theory, lets think back to Dave his imaginary friend. Hurley started seeing 'Dave' (MIB manifested as Dave) again on the island. 'Dave' tried to convince Hurley that none of what was happening was real, and to jump off the edge of the cliff. Hurley almost did it. Once again, though, I don;t think MIB was counting on Libby being there. Perhaps Libbys only real reason for being brought to the island, was the make sure Hurley didn't make it off of the cliff. Jacobs handy work I would assume.

So there you have it. I think those two are very important because MIB has been trying to take them out for some reason, but failed because Jacob was one step ahead of him.