the cryengine 3 movie with the nuke going off looked pretty damn realistic to me.

the definition of real is not quite as simple as throwing together a great engine and put in some objects and characters. good games are probably handled by a director who knows how to give a real movie feel. raw processing power with no direction can "feel" like crap. there are so many little things that we ignore in every day life, that when missing from a game can quickly take away the experience.