I just read the comment that was written about the episode "Heart" claiming that it was so sad that the viewer wanted something more upbeat to happen to Sam. I agree that it was sad and I cried, too. And... yes... I, too, noticed a large tear drop from Dean's eye. But, I think that the writers have a goal in giving Sam all of these hardships. Perhaps its to push Sam over the brink to his darker side, or maybe they want to showcase all of his suffering for something that is coming down the line. I feel that it is done on purpose and we will understand why later in this season or the next. Very good writing, guys! Between "Roadkill" and "Heart", this has been some of the best writing on the show that I've seen so far. You've outdone yourself. However, I'm glad that you do write lighter episodes every now and then.
Gabi