Man on Fire (2004)

Without getting too excited about him, I am happy to admit that Denzel Washington is a fine actor who manages to take on sufficiently different roles to keep his appearances of interest.  However I am not sure I can buy him as a trained government killer.  Now retired and with a booze problem, he is taken on by a rich Mexican family as a bodyguard for their daughter -- the precocious Dakota Fanning yet again.  Despite his trying to keep an emotional distance from his young charge, he warms to her and then goes 100% beserk when she is kidnapped and believed killed.  The balance of the movie (and it is a long one) has him seeking out those responsible and dealing with them with ultra-violence.  By the end he probably feels redeemed and can now face whatever he must, but it's a bloody slog for the viewer.