Character Analysis
The Friend in Need
All you have to know about our lovable, affectionate Samwise Gamgee comes in a quote at the end of the movie. Frodo and Sam are adorkably pretending to be hobbit kiddos, listening to the epic tale of Frodo And The Ring. Sam goes on for a while, playing at being a child that's super-into hearing about Frodo… but Frodo cuts him off. In character, he says:
FRODO: "Well, you've left out one of the chief characters: Samwise the Brave. I want to hear more about Sam. Frodo wouldn't have got far without Sam."
Sam is such a humble and loyal friend that he thinks Frodo is just messing with him. Emphasis on the "humble"—he doesn't even consider that his own heroics are worth mentioning except as a joke. This is just who Sam is: a hobbit, a gardener, and someone whose aspirations in life used to involve Rosie and now involve getting home in one piece. He's not ambitious at all, which is probably why he's such a good companion for Frodo.
That's not to say Frodo is a naturally evil or greedy hobbit, but with the Ring is slowly wearing on him (no pun intended), and he needs someone by his side who he can trust with the burden. He needs someone who won't challenge him or compete with him for the Ring, but will be happy serving him and looking after him. Sam fits this role perfectly. He's always concerned about Frodo's well-being—he's constantly asking him how he feels and telling him to get more sleep.
Sam's like the den mother of the group; he's always got it together. Whether he's keeping an eye on Gollum or cooking some stew; without him, everyone knows their whole journey to Mordor would have fallen apart somewhere between Emyn Muil and the Black Gate. Frodo may be bearing the Ring, but Sam is bearing the burden of Frodo, and of Gollum, and of being the only one who still has any hopefulness or optimism left in their dark journey.
In Need of an Enemy
And let's be honest, Frodo isn't exactly making this easy on him. Poor Sam is only trying to help. We think he's pretty sensible in not trusting a creature whose mind and body seem to have been literally warped by its obsession with the Ring for the last half a millennium. But Frodo trusts Gollum nonetheless, and Sam's carefulness only serves to drive a wedge between him and Frodo, resulting in Frodo almost driving a sword through Sam's throat.
Well, okay, maybe Sam is more than just "careful" around Gollum. In fact, he can actually be a bit mean:
GOLLUM: It tries to chokes us! We can't eats Hobbit food! We must starve!
SAM: Well starve then, and good riddance!
GOLLUM: Oh, cruel Hobbit. It does not care if we be hungry, does not care if we should die. Not like master; master cares; master knows. Yes, Precious. Once it takes hold of us it never lets go.
Yes, yes, we know that at the end of the film Gollum plans to betray the hobbits and that Sam was right all along. But hindsight is 20/20 as they say, and this seems like a poor excuse for how Sam behaves toward poor Sméagol. As much as we'd love to think of Sam as the shining light, the one true noble soul of the film who is forever incorruptible, this just isn't realistic.
This makes us ask: what if the tables were turned and Sam was the Ring bearer? Would he want to outright kill Gollum? Could he resist the temptations of the Ring as long as Frodo has? It's easy for us to label Sam as the true hero of the journey and Frodo as someone who's off in his own world of rings and dead kings. But this may just be a product of their situation and of not their true character.
But we're starting to sound like Frodo, with all this doubting Sam talk. Sam's wonderful. And what makes Sam so wonderful is that his love and loyalty are unconditional. It doesn't matter that Frodo trusts Gollum despite Sam's warnings, or that Frodo is getting more violent and more burdened. Sam is going to be there until the very end, whichever (or whoever's) end that may be. It's even going to take more than Frodo nearly cutting off his head with a sword to drive Sam away from his best friend (which is more than we can say for ourselves; one near decapitation and we're out).
Sam's Timeline