By how many points did alphago win against Lee Se-dol?
The DeepMind channel on Youtube has a short review of each game by Michael Redmond 9P.

At the end of the summary for game 1, Michael estimates that black is slightly ahead on the board. When you factor in the 7.5 point komi, it means that the final score would have been around 5.5 in favor of AlphaGo.

Note that 


  AlphaGo does not attempt to maximize its points or its margin of victory. It tries to maximize its probability of winning.


[Source: wired]