I truly think that the greatest of all of Samwise Gamgee's great deeds is the mortal blows to Shelob. Shelob the spawn of Ungoliant. Ungoliant who destroyed the trees in Valinor at Morgoth's bidding. This deed ranks above even Gandalf's slaying of the Balrog as far as sheer badassery goes.
Here is this little Hobbit who's spent his life gardening and just admiring elves as a thing in songs and far above him doing a deed so great that any elf lord in all the history of Arda would bow to him for it. The orcs thought there was a mighty elf warrior in the passage and they weren't too far off. Any ancient hero of elven lore would have ranked slaying the spawn of Ungoliant as one if not the greatest of his achievements.
There may be no more amazing deed of heroism in all the trilogy than this. Shelob the last descendant of the most foul of all creatures brought down by Samwise Gamgee. It's even more epic than Eowyn and Merry slaying the Witch-King for this is a remnant of a far more ancient evil. An evil that never was anything but evil. No tragic seduction by the Dark Lord here. Just the spawn of the light eating wholly evil giant spider who terrified even Morgoth.
