Some of Stallone's films have been truly excellent, Copland especially has been mentioned.
However, I can't believe the number of people saying they don't rate the Rocky movies, the first one is one of the best pictures ever made, winning three Oscars in 1977 and being nominated for seven more, including best Leading Actor and Best Writing for Stallone (only Chaplin for The Great Dictator and Welles for Citizen Kane have done the same).
It's a truly great film in my opinion.