I don't think Titanic deserves all the hate it has now picked up since its release. In a way, I think it was a victim of its own success.
That said, it did have flaws. The script was very hammy, and there were many other characters on board the ship who could've benefited from more time in front of the camera and more development. That said, that would probably have harmed the 'love story' angle, so it's swings and roundabouts.
But no-one can deny that it is a brilliantly directed, emotive and epic piece of cinema. It is one of the few films that has complete power over me emotionally when the ship sinks. I don't think I've ever cried in a film, but this is easily the closest I've got to it.