First Michael Lopez wrote about Titanic; then I wrote about Titanic, and then he wrote about Titanic some more. So it only seems right that I proceed to, yes, write a little more about Titanic.
Basically, I just want to respond to the fourth point in Michael's second post, in which he's still really hung up over the fact that Rose doesn't sell the diamond and then live off the money (or something similar), which would make it a lot more feasible to "make every moment count". The problem I'm having with Michael's argument here is that he's attacking Rose for this, but as far as I can see, what she's doing is putting Jack's philosophy into play. Jack has, by the end of the film, been pretty much conclusively established as a guy who would rather be poor than rich, because he knows how to get by. Now, whether that's realistic or not is open to question, but I don't think it's so easy to damn Rose when what she really does after the sinking is start living what was not actually her life, but Jack's. (Take a good look at those photos on Rose's shelf, the ones that Michael mentioned in his earlier post: the first one we see has her standing on a horse on a beach, in front of a roller coaster. This is an exact allusion to something Jack had said they would do when they left the ship, early in the film.)
I also think that the film also establishes that Rose would really rather be poor, so I think her decision to do nothing with the diamond is in keeping with her character. She has absolutely no desire to marry just to maintain her family's station, nor does she want to remain in that "station" at all.
At its heart, the love story of Titanic is another version of Lady and the Tramp, although in this case the Lady decides to become a tramp herself, rather than see the Tramp "rehabilitated" to become a "Gentleman". I don't know, I guess from a standpoint of utilitarian ethics I can see the argument that Rose shouldn't have kept the diamond all those years. But I can't bring myself to hate Rose.
But then, this could simply be because she's a ravishing redhead.
(Full disclosure, I suppose: To this day, I still love Titanic, even if the love story really is pretty goofy.)