Part 3 and 4 aren't uploaded yet, I'll post them as soon as they are.
I think the last scene will be Jack and Hurley sitting side by side and they'll look at each other and Jack will smile like "We had some crazy times, Hurlomobile." And Hurley will nod and smile like "we sure did." and that will be the end. I had to write it down because if that is the ending and I say "Wow, that's exactly what I expected." No one will believe me. So there it is. The final scene of LOST!