My vote goes to Boyle, even though I think Aronofsky may be the better director. The thing is, Danny Boyle's got a much more solid track record than Aronofsky. Aronofsky seems like he has more potential to do great things than Boyle, but Boyle has proven himself more in the past. Of course I haven't seen either 127 Hours or Black Swan, and those films have the potential to sway my opinion.
Fincher is someone I see as talented, but I don't feel like he brings as much to the table as Boyle or Aronofsky.