Charisma can help you get out of many sticky situations. In my last playthrough of Fallout New Vegas, I pretty much talked my way through the whole game with the help of high charisma.
Today's video from Bethesda highlights this S.P.E.C.I.A.L. for Fallout 4. From bartering to relationships to addiction, charisma can benefit you in several ways. I'm thinking of going through my first playthrough of Fallout 4 with a high luck and high charisma character as it was pretty fun and different from my usual run and gun style.
So far these videos that Bethesda are putting out are absolute gold and I can't for an entire compilation of them all in one video for viewing.