Um... Such a choice... Twilight or Titanic. I didn't care for either fully. They both had potential, but didn't fully meet it. With Twilight, the synopsis was good, but the way it was executed and the material left a bad taste in my mouth. Though it was a good escape piece, it was one I couldn't fully emerse myself into because like I said, some of the material just left a bad taste in my mouth. Especially in the "romance" department as it seemed like a mutual dance of manipulation and I've been pretty vocal about what I dislike about Jacob and Renesmee (or basically the whole thing about the wolves imprinting thing).
Titanic... I remember seeing it when I was 14 with my sister and mother. I had a cold starting at the time and found myself laughing more than anything at stuff that was unintentionally funny. Though I liked the whole historic romance thing, I found it really sappy and boring instead of "monumentally classic." Needless to say, after watching it, I've sworn off James Cameron because it seemed like he was more interested in effects than storyline.
So, yeah. Neither.