In my not remotely humble opinion, the first Superman film is the greatest superhero film of all time. The second could have been its equal, but although it is damaged goods (the ideal cut would be somewhere between Richard Lester's and Richard Donner's version) its still pretty damn good. The third is largely disposable, give or take an "evil Superman" sequence towards the end of act two, and the fourth isn't worth your time (trust me). :)