You can be nice, horrid, honest, violent, kind.. you choose the job he does, and then actually can control him (whether it be a boxer, a cake maker, a plumber or a thief).
You choose who his friends are, whom he is romantically involved with, his sexuality, beliefs etc.
You can drive places or go on holiday, start a family, push old women in front of cars, run from the police, be arrested, become a policeman...
Just imagine how frigging awesome this would be.
Maybe they could do it online, with an ever growing world, and new jobs or hobbies or whatever can be added and uploaded by developers all the time.
You now, you go for a game of footy with mates and get a Fifa kind of set up, or you go for a drive and it's alla bit Gran Turismo.
Anyway it will ever happen, but that is my gaming fantasy.