Listing all differences I noticed between the two Oceanic Flight 815's...the original that ended up crashing on the island, and the later flight that did not crash.

1. Jack is afraid of turbulence now, where Rose was afraid originally

2. Hurley is the luckiest man alive later

3. Jack has lots of deja-vu feelings

4. Charlie aspirates Heroin in an act of suicide, or by accident, in the bathroom whereas Charlie just went to the restroom to take a heroin hit before.
Charlie tells Jack he "was supposed to die".

5. Jack has a mysterious scar, wound, tatoo on his neck

6. DESMOND.

7. Sawyer tells Hurley to be careful with who he tells that he's won the lottery, because people will take advantage of him....can't help but wonder if he's still a conman or no?

8. Stewardess gives Jack only one bottle of liquor, originally it was 2.

9. Locke: At the beginning of the flight it was impossible to wheel him onto the airplane, but at the end of the flight now, he is able to be wheeled? Some feel his outlook is more positive....did he go on the walkabout or is he lying to Boone?

10. Boone is not accompanied by Shannon.

I'm sure there are more...