I haven't seen Kingdom of Heaven yet and may wait for it to come on DVD or cable. However, I think the Monk is being unfair for lumping Troy with Kingdom of Heaven. (I haven't seen Alexander either but frankly expectations are very low given that the callow Colin Farrell is in the lead role. BTW, that would be a great way to kill the Bond franchise.)
For those of you who haven't seen it Troy is a very good, very entertaining movie. Yes, they made some changes to the mythology - the Trojan War is now 15 days instead of 10 years but it's a two hour movie not a miniseries. Also I don't remember a Briseis in the story though her addition did nothing to detract from the overall story.
The cast, with notable exception, was excellent. Brad Pitt is superb as a haughty, aloof and invincible Achilles and is completely credible in the fight scenes. [The womenfolk will swoon over him.] Eric Bana and Orlando Bloom are perfectly set as the serious, noble Hector and the carefree, careless Paris. Sean Bean does a very good, understated role as Odyesseus and old Braveheart hands Brian Cox and Brendan Gleeson reprise perfectly a calculating, megalomaniacal Agamemnon and his cuckolded brother Menelaus. Saffron Burrows is lovely and tragic as Andromache and Peter O'Toole fine as the aged, deluded Priam. The big disappointment was Helen Kruger, while pretty, is too new and far too bland to be Helen, the face who launched a thousand ships.
The sets of Troy were magnificent and battle scenes very well filmed. The approach of the Greek fleet to Troy and the opening battle gave a sense of the vastness of the Greek effort. For someone who knows the story well the sense of tragedy was well done and evident throughout the film.
Well worth your time folks.