I went to see the Odyssey movie (in IMAX) last night. It's an impressive film, though far too loud. It stayed reasonably close to the epic poem, though with a few (largely unimportant) changes, like the role and timing of the lotus flower incident. There were a few glaring anachronisms, notably the repeated references to the Sea Peoples and (far worse) Odysseus' reference to the "Age of Bronze".
What was most interesting to me was the philosophical focus of the movie around Zeus' Law (roughly: be kind and hospitable to strangers; if you're such a guest, respect your host) and how that permeated the whole movie. I won't say more, for fear of thematic spoilers, but I found it quite noticeable, and not just in the obvious place, and quite interesting.
The cinematography was superb; so were the special effects.
Anyway: highly recommended, and though you don't need to be familiar with the source material it helps. (I don't see many movies in theaters; oddly enough, as best I recall the last one I saw before this one was Nolan's "Oppenheimer".)