Cool topic, but from a fairly old start. I'm glad it was resurected, because I wasn't around when most people posted.
Since all three movies are out, I guess no one will mind if I pull from all three.
The part that really affects me the most is atually in the FotR...it was mentioned a lot already in this thread, but it's an awesome part in the movie - when Sam goes out to Frodo in the Anduin. And it when he did it, it wasn't 'I can try to go, or I can actually stay here and do as he says, but, no, I ought to go', it was more like 'I've got to get to Frodo...he can't go without me. He'd die!' I don't believe there was a thought of himself in that act. No choice, in his mind.
In the RotK when he comes back through Shelob's Lair and fights Shelob for him. It was pretty much the same mind set, I think.
And again in the RotK, after the ring was destroyed and they were on a rock. Sam finally thinks of himself and starts crying because he loved Rosie, and Frodo crawls over to him and puts an arm about his shoulders. That part is so sweet. Frodo's himself again, and he's close to Sam once more.
I would be more eloquent on this matter, I'm sure, but it's too late to do something like that.
-Folwren