The ending of 'The Lord of the Rings' is this sprawling, multi-layered thing that honestly took me a couple reads to really feel. Frodo and Sam make it to Mount Doom, Frodo claims the Ring for himself at the last second—that part always gets me, the corruption is absolute—and then Gollum bites his finger off and falls in with it. The eagles show up, which, okay, a bit of a deus ex machina but I’ll allow it.
Then you get the long wind-down: the crowning of Aragorn, the hobbits returning to a Shire that’s been messed up by Saruman. They sort that out, but things aren’t the same. The scouring of the Shire chapter is vital, I think; it shows they didn’t just go on an adventure, they came back changed and had to fight for home too. And then Frodo can’t find peace, his wounds from Weathertop and the spider sting and the Ring itself never really heal. He sails west with Gandalf and the elves. It’s bittersweet, not a clean happy ending, which feels more true to the cost of the whole war.
I always get a bit choked up at Sam’s final line, "Well, I’m back." He gets to have the normal life Frodo saved for him.