I'm surprised nobody has mentioned Dom Perignon, that's the champagne I'd put at the top of the list, followed probably by Bollinger's Grande Année. I'm yet to taste the Winston Churchill, I need to add that to my list.
In no particular order:

• I'd like to see an Armagnac make an appearance as a digestif.
• There are as many whisky choices as there are palates on a plane but I think a proper single malt scotch should feature. Ardbeg's Uigeadail has been a personal favourite recently but it'd need a bit of water because it comes at 55% ABV.
• And as mentioned by multiple people above, I'd change the water too. It should be Évian and Badoit. But then we'd really bankrupt BA