There is only a couple sandbox games which seem to do it right.
One I would definitely recommend is The Regional Manager. Only warning -- you have to play the psychopatic corpo leader route, the romantic path is not yet coded by the dev . Tons of content. I guess it works because it has a huge number of characters (over 20 I think), but they all are woven sorta seamlessly in your life. Also you have built-in hints and options to skip money earning or tiredness. Makes for a very satisfying run.
It does have sandbox, but it's really quite good, imo. It also has these moments when you see a random character and talk with her, and think, damn, why can't I get her.
And half a game later you land in position to do things with her. But you'd never think you actually would get her, we're talking like side characters.