Ha ha, the mistakes get on my nerves, too. Be sure to check out Moviemistakes.com for a complete listing. I knew about that site years ago, and contributed one or two myself.
The big ones which annoy: the wad of Dwarven mucous that slides out Gimli's Dwarven nose while he shouts "I will DIE before I see the Ring in the hands of an ELF!"
It's also MEGA-annoying to see TWO Legolas stunt-riders riding out in the Helm's Deep charge. You may not want to watch it, since it might forever shadow your future viewings. But when Theoden leads the charge out the causeway, there are TWO blond-braided graceful figures that look somewhat like Legolas, riding out the ramp. Plus, if you look carefully, the extras playing the soldiers were obviously told to swing their swords and they'll add the creatures in later. Yet while they are swinging their swords, most of the work is done by the horses, plowing into the Uruks and sending them flying off ere one is cut by a blade.
Same thing with the Warg battle. Right after they're finishing up the fight, you can see some riders in the background, looking strikingly goofy, just swinging their blades in the air as if for fun! AUGH, it drives me NUTS!
