Five...
Lisa Schwarzbaum of Entertainment Weekly: "All hail The Lord of the Rings: The Return of the King! I can't think of another film trilogy that ends in such glory, or another monumental work of sustained storytelling that surges ahead with so much inventiveness and ardor. The conclusion of Peter Jackson's masterwork is passionate and literate, detailed and expansive, and it's conceived with a risk-taking flair for old-fashioned movie magic at its most precious." And, we've got another clip! Gollum connives above Minas Morgul...relatively spoilerish. (If you do watch it, notice how he licks his lips. It's amazing CGI.)
I never trust Schwarzbaum -- her evaluation of movies almost always conflicts with mine. So now I'm worried!
Well, she liked Fellowship a lot too. (Owen Gleiberman, for his part, gave Two Towers a B- and ranted on about fantasy.) If it helps to allay your fears, I have yet to find a negative review.
100% at Rotten Tomatoes and Metacritic. But it's still early yet. There will be at least one Tibor Fischer-like contrarian.