My favorites:
8. Gold: The Stretchy Element.
The ring, which is seen to be at least two inches in diameter at the beginning to fit the polish sausage-sized finger of Sauron, suddenly fits Frodo's child-sized finger later. I guess this movie takes place in a world where rings magically change sizes on their own.
13. Did someone say plot hole?
Liv Tyler's character is seen easily defeating nine strong supernatural beings, even though she is clearly a woman.
17. Invisible Implausibility.
Every time Frodo or Bilbo went invisible with the ring they should have also gone BLIND. Your eyes cannot function unless light is reflected off the cornea. If light passes through it (as must be the case with invisibility) sight is no longer possible. Also, rings do not turn you invisible.
20. Magic Mechanics.
Experts on the occult say in order for a wizard to floorspin a fully-grown man like Gandalf, he'd need three magical staffs, not two.
22. Go-Go Gadget Arrow Sprouter.
Legolas shoots arrow after arrow at his enemies, and yet the number of arrows in his quiver never decreases. I guess elves have glands on their back that secrete arrows.
25. Propaganda.
The Elves, clearly the most advanced and wise species, are also clearly gay.
26. Speaking of Elves...
Elves are beautiful and wise and tall? Great warriors? Makers of fine lightweight weapons? Our modern knowledge of elves has observed only an ability to make cookies and toys. All the elves in the film are portrayed as living in a warm paradise (Rivendell) but our own information tells us the aforementioned group of toymaking elves work and thrive in the arctic. Hey, Mr. Jackson: Research is half of writing.
27. Homage or theft?
The "happy village of little people" idea was stolen from Willow.
28. Homage or theft II?
The wise old wizard character was stolen from Harry Potter.
29. Homage or theft III?
The "travelling on our quest through a corn field" scene was stolen from Shrek.
30. Homage or theft IV?
The character of the rebellious-but-helpful Ranger was stolen from Val Kilmer in Willow.
31. Homage or theft V?
The concept of the violent dwarf was based on Al Pacino.
32. Homage or theft VI?
The "old man looking through the door hatch at the approaching little people" scene was stolen from A Clockwork Orange.
34. Homage or theft VIII?
The incident with the flock of evil magical spying crows serving the All-Seeing Eye was based on an actual incident.
36. Homage or theft X?
The character of Elrond was based on Agent Smith from The Matrix.
38. Realism, schmealism.
Liv Tyler's immortal elf volunteers to give up her eternal life for a single romance with a human man. Could any man really be that well endowed? I find it unlikely.
45. Casting.
Why couldn't Frodo have been played by Christopher Walken?
46. Casting, II.
Why couldn't Gandalf have been played by Bruce Campbell?
47. Casting, III.
Why couldn't Bilbo have been played by Vin Diesel?
48. Casting, IV.
Why couldn't Strider have been played by a monkey?
50. What's that smell?
As bad as the Lucasfilm leaks were with his last film, the filmmakers of Return of the King already have the novelization out in paperback. I've seen it at Barnes & Noble already. As if we needed any less of a reason to go see it.
His apology is pretty good too.