Wish I could help but I have most of the minor works, with UT being the only one that comes to mind.

Still nobody? Well, I'll tell you then.
Tom Bombadil calls Farmer Maggot "Penny-wise tub-on-legs!" in "Bombadil goes boating"

And here is a new "insult", I hope easier to locate!

Sam to Shelob, by any chance?

Exactly! :)

Have fun!

Grishnakh to Ugluk, TTT pg 55

And that's my 100th post! :D

Yep. You're right.

Someone else can take my turn.

OK, here we go:

Feanor to Olwe, by any chance?

Exactly!
 

Your turn again, Dimturiel! :)

Thank you :)

I guess that's Thingol to Beren?

That's right! :)

Thank you, Dimturiel! (btw, I like your signature! Where does it come from?)

Here's another nice insult:

This has to be Thorin to Bilbo.

Exactly!

(it seems we two are alone here on this thread... What's become of Sleepy?)

So it seems it's my turn again. (By the way, Guinevere I'm glad you like my sig. :) It's from a poem by Yeates called "Stollen child".)
Good luck! :)

That's the one. Welcome to the Downs! :)

I have no idea... :confused:

Since its been about an age here's one

This would be Húrin mocking Morgoth:

"Blind you are, Morgoth Bauglir, and blind shall ever be, seeing only the dark."

Well done, too easy.. the question itself was insulting

Not at all! I am glad that you revived the thread, hewhoaresesinmight! :)

Here's a new insult, directed at all those who have neglected this thread for so long ;)

Is that when Sam and Frodo get stopped by the orcs in mordor?

That's right! The orc captain to diguised Frodo & Sam.

Your turn again!

I hope you guys don't mind me putting up the next one. :)

"Get thee gone from my gate, thou jail-crow of.....!" (last word omitted to make it a bit harder ;) ).

Feanor to Melkor (as he then was)

The last word is 'Mandos' as well.

I'm bored, so here goes... Are movie insults allowed? I don't know if this is in the books...

You sea rats!

That was uttered by the Orc with the interesting headpiece at the docks to whom he thought was a ship full of Corsairs (but was actually Aragorn and friends). The exact quote is: "Late as usual, pirate scum! There's knife work here needs doing. Come on, you sea rats! Get out off your ships!"

Right!

"Who are these miserable persons?"

This was said by the Great Goblin about the Dwarves and Bilbo.

Yes, along with several other insults that would've have really given it away!
Great job! Your turn.

Thank you! Here you are.

That would be the Mouth of Sauron, referring to terms with the rabble of Gondor and its deluded allies.

Yep, that's the one.

"uncouth race"