Never underestimate 'big Willie' box office returns.

The mega-star's last blockbuster, 'I Am Legend,' exceeded industry estimates by almost $30 million its opening weekend, hauling in $77 million in early December.

But how the heck did Will Smith graduate from Philadelphia's 'Fresh Prince' to a two-time Oscar-nominated actor and the reigning blockbuster king?

It's called careful careerism with a good head for populist fare.

Here's a look back at how Smith has balanced mass popularity with an eye toward artistic credibility.

Related: He may be 'Legend,' but what about Oscar?