...what would it be? I'm thinking big with this one, so be creative with it, instead of just saying things like "the Man in Black should have been killed in a cooler way".
If I had any creative influence over LOST, I would have given the centricity a little more symmetry. As one of the key aspects of the presentation of LOST's narrative, a little tweaking here and there would have been beneficial in my opinion. Jack had five centrics in Season 1 and Boone only 1, and I would have made the cast a little more "ensemble" through the centricity. The requirement of a full episode per character may have also forced the writers to create a story for every character in each season, and not let people drift in the background as Miles and Frank did in Season 6 and Jin did in Season 4.
So for the first three seasons, each character (about 12 in all) would have two flashback episodes, not in any specific order relative to each other, but evenly spread. Season 4 and 5 would be a little harder to manage, since the non-Oceanic 6ers did not have flashforwards for a very good reason. Season 6 was probably the most balanced of all in the end, with one completely centric episode per character then a few joint episodes.
Another related thing that I would have changed is the over-use (in my opinion) of multi-centrics. Maybe it's just the OCD in me to want to slot every episode into the right place but a few of the shared or non-centric episodes could easily have been tweaked to fit one specific character. "Because You Left" in particular could almost count as a Faraday episode, and "The Last Recruit" could have gone to Claire, with a few modifications. When there's a character behind the episode you see all the events through the context of that character, and it has a very interesting effect on the story (cf. "Follow the Leader" as seen through Richard's eyes).
I know this is a slightly unrealistic thing to want to change, and is only something that comes from hindsight. But the producers (1) need to have their main stars to market and (2) can't know how audiences are going to react to something before it goes out. But it's an interesting thought. What do you guys think?
Any other changes you would make?