Charisma, of course.
You can have the best ideas in the world with your Int 18, but if you can't sell them profitably what's the use? Also, IMHO no matter how intelligent you are by yourself, being a good teamwork player gets you further...
As for wisdom, maybe you sleep better at night when you don't look at today's world with a Wis 18...
Con is important not to be less than average. A 12 is IMHO fine.
Dex shouldn't be less than average either so you don't spill your soft drink over expensive books and tech items all too often. Also less typos ;-)
Strength - well, I have a lot and I don't really have a use for it except for opening stuck jars. 10 would be fine.