The saddest scene in all of Lost

You all must have a guess, but unless you chose the following, you are very, very wrong.

http://www.youtube.com/watch?v=n_SxoS-Gd_s

Some people think the action was stupid, that it was a useless loss of life, but the people with souls will see it was extremely touching that he would rather die with her than leave her alone to die at the end.