Statistically, what opening has white won with the most?
Such as, 1.e4 e5 2?
What is the move that white makes that has won the most games?
Here is a tongue-in-cheek answer. The 4 move checkmate (1. e4 e5 2.Qf3 Nc6 3.Bc4 Bc5?? 4.Qxf7#) is an opening where White has won 100% of the time.
The reason why I post this answer is to highlight a few flaws in the question you asked:
This article says there are 5,362 possible positions after White's second move, so are you asking which of those positions ends in the highest percentage of won games for White? Choosing that move seems a little arbitrary as the cut-off point for the "opening".
On the other hand if you were to look just at the first move, you should be able to find that out quite easily for any given database of games, but you quickly run into problems with sample size. For example, in the Chessgames.com database (over 750,000 games) you can see that the most successful first move by this definition is 1.Na3, with which White wins 78.3% of the time! Unfortunately this is from a sample of 23 games...
Due to the fact that opponents are not all consistent in the moves, it is impossible for there to be a 'best' move, but there can be the most appropriate move for a set circumstance.
Although simple, I generally like to open my getting my knights and bishops out first, and then going on to force the game in order to bring about victory.
Hard to say, as opening trees are biased as number of games played and player strengths are different. And the score difference between best scoring openings is very little, we can say statistically insignificant. So it's really hard to say.
Therefore, if you ask this for building an opening repertoire, don't do it. But if ask this just for curiosity, then you have the answer.