I like a good story. A character to me is a pile of numbers and notes, no matter how much I've enjoy playing it or how long. If I'm playing in a game and the rest of the party might be saved by my staying back to buy them time fighting the BBEG, then I'm gonna do it. My character might die (though it's not my intention to commit PC suicide), but if it advances the storyline or makes for good drama, I'm gonna do it. I can always roll up another!