This might be an observation, although not a particularly well-honed one, that in horror movies, the fat guy is usually one of the first people to get killed. Prior to watching LOST, I had assumed that Hurley(Hugo Reyes) would be the first survivor to "leave the Island", as he lacked the survival instincts of Locke, Sawyer and Sayid as well as(I am loath to say this) the svelte physique of Jack and Boone. But, at the very end of the series, Hurley becomes the protector of the Island and Jack's well, dead. I wonder why?
I think that Hurley survived to the very end and became Jacob's replacement was because his life was effectively a clean slate compared to a conman(Sawyer), a convicted and hot felon(Kate), a doctor with an obsession for fixing things(Jack), a man who tortured and murdered people as an occupation(Sayid), a drug-addicted has-been rockstar(Charlie) among others. You could say therefore that Hurley had "good karma", meaning that his path would take a much more positive direction.
Also, compared to say Jack, Sawyer, Locke etc, Hurley is the picture of gentleness, tolerance, inclusiveness and understanding. An example of him doing his part to make everyone feel welcome in the makeshift community of the survivors was giving Sawyer a heads-up regarding his behaviour, ie that if he carried on the way he was, he'd be isolated from the rest of the group. In Season 4, Hurley handing a chocolate bar to Ben seems to show that although Ben was responsible(albeit indirectly) for the deaths of the woman he loved(Libby) and his best friend(Charlie), he's actually quite forgiving and doesn't hold grudges. During "The End", FST Hurley tells Sayid that he is a good person, despite the latter's what can only be described as chequered past, oh and reunites Sayid with Shannon too.
Despite what happens to him and others close to him, Hurley maintains his sunnyish disposition. I found this to be quite inspiring as any other person would have been driven to despair by these circumstances, not so for Hurley.
I'm sure you've all got your own thoughts on Hurley/Hugo, LOST's "Gentle Giant" and protector of the Island