9. Steven Spielberg and Will Smith
Steven Spielberg has spent his entire career trying to replicate what Hitchcock had with Jimmy Stewart, his nice-as-pie, all-American star. He has it in Tom Hanks and Tom Cruise, but imagine what Spielberg could do with Will Smith. As Hitch did with Stewart, Spielberg likes to take a slight peek at the darker side of the squeaky clean American hero, casting the biggest, most affable movie stars around as his leads then putting a twist on their formula (see Hanks in Saving Private Ryan, or Cruise in Minority Report). It's not something that's been properly examined in Smith (he had the chance with Tarantino but turned it down) and the results could be very interesting. And though it seems 'Berg has wanted to work with Smith for a while (the Oldboy remake and the Chicago Seven movie being two abandoned collaborations), it still just hasn't happened.