Might just be me, but it's pretty amusing when Morgoth and Ungoliant get into their argument. Ungoliant tells Morgoth that, for her help, she wants to eat the world. Morgoth basically replies "You can't eat the world, I have to rule it!"
Beren tries to hold off Carcharoth with a Silmaril in his hand. Carcharoth responds by eating Beren's hand. Om nom.
Beren pronounces, "Even now a Silmaril is in my hand." He subsequently holds up his bloody stump of where his hand used to be.
Haleth cracking the only joke in the whole book, and it's actually a pretty good one, if rather dark. Bascially, 'If Thingol thinks I'm going to join up with Melkor after what he did to my family and my people, then the minds of Elves are strange, scary places.'
Beren remarking to Thingol that Elven-kings must not think much of their daughters if they're willing to marry them off in exchange for some jewelry. This in response to an Engagement Challenge that amounts to "Travel to the hellish fortress filled with countless legions and demons and steal the most brilliant, beautiful, and masterfully crafted objects to ever exist from the most powerful being in existence".
But then again, it nicely sums up what all the Edain (the race of Men) are probably thinking about this war they stumbled into ("So let me get this straight, all this death and suffering is happening because of three lightbulbs?").
The creation of the Ents—Yavanna has a hissy fit when Aule makes the Dwarves, as he didn't tell her about it, or ask for her help, and aren't the tree-hugging pacifists she would prefer. She then storms out, gets permission from Manwe to create a race of guardians, the Ents, and then comes back gloat to her husband, who is busy in his forge and doesn't even look up from his work.