I'm looking forward to
Return of the King. I don't intend to watch the trailer or seek out spoilers, though. I want to go to the theater and enjoy the movie.
I've read (and re-read) the books, though, so I have some idea of what's to come. One thing I noticed about
The Fellowship of the Ring and
The Two Towers is that they both took liberties with the original sequence of events for dramatic purposes. I heartily approve of that; it results in great movies. For example, Boromir didn't die in the first book (and Aragorn didn't kill the chief orc), and there are some things coming up in
Return of the King that actually took place in the second book.
The Fellowship of the Ring ended on a foreshadowing note (you knew that Aragon, Gimli, and Legolas would be searching for Merry and Pippin in the next movie and "hunting orcs").
The Two Towers ended on yet another foreshadowing note: you know that Gollum is leading Frodo and Sam into a trap.
The Two Towers, like its predecessor, began with an exciting battle scene (involving Gandalf and the Balrog). So I'm expecting
Return of the King to begin on a similarly exciting note. You heard Gollum--he's taking Frodo and Sam to meet
her.
The scene with Shelob is my favorite scene of all in the books. If the filmmakers can pull it off, it might be the scariest thing we've ever seen on film. If you haven't read the book, I don't want to spoil it, but I'll say this. When Frodo and Sam head into Mordor, they don't have anyone with them to protect them. Gandalf, Aragorn, Boromir, Gimli, and Legolas are long gone. If the two hobbits get into a fix, they have to get out of it all by themselves.
There's a significant difference between the books and the movies. In the books, the hobbits are very stealthy (not clumsy), and they can hold their own in a sword fight. In
The Two Towers (the movie), when Merry and Pippin drew their swords against the orcs, the orcs simply swept them up and carried them off. That's not what happened in the book. In the book, Merry killed and dismembered so many of them (he chopped off their arms and fingers), they had to hit him on the head really hard to make him stop, since they were under orders not to kill him. In the books, Merry and Pippin go on to become the greatest halfling warriors the Shire has ever known (as well great historians). As a result, I don't think the way they are portrayed in the movies is all that fair or accurate. But the point is, they aren't completely helpless in a fight, no matter how they are portrayed in the movies.
SPOILERS
In
Return of the King, we'll see Sam rise to the occasion in spite of his modesty. If you've ever read the "LOTR Secret Diaries" (a silly spoof that someone put on the internet), you'll see there's some truth to the line, "Sam will kill him if he tries anything."

Frodo all but gives up, and he vows never to raise a sword again because he has seen too much killing, so Sam steps up to the plate, never realizing how great a hero he really is. That's why the scene with Shelob (one of the scariest monsters that has ever lived) is my favorite scene of all, and I'm really looking forward to it.