OK, well the end is over for Lost. Most people hated the ending and some loved the ending. I for one was pleased with the ending. This theory is all about Ben and Hurley. My close friends and I want to know what the regime was like with them 2 in control. I think that it was very peaceful with them 2 in control, not a "look there is a plane crash" peaceful, but a more soothing and more easy going type of administration. There first order of business: Send Desmond home. He didn't need to be back on the island, he was happy with Penny and Lil Charlie. Hurley is a man that keeps his word, and he sent Desmond home and he returned to be with the 2 people he always cared about. 2nd order of business: Trust. Hurley and Ben didn't always trust each other, (remember the hot pocket incident from season 5) and Ben was not the most liked guy until the end of Season 6. The island needed them to stay, hurley was a mess off the island and with Hurley there, it was a place of serious business and comedic relief.
What I am getting with this theory is that Ben and Hurley had the island for a very long time, possibly with more plane crashes and more others. But Like Jack said, the island needed Hurley and Hurley needed the island, just like Ben. Ben had NOTHING on the real world. No family or anything, so being on the island with someone that he trusted was good.
The Death of them was most likely on island and that they lived there for a VERY Long time...
this is my 1st theory so let me know what you think