2001 is one weird-ass movie. I think Kubrick was way too much into 'shrooms while filming it. Visually, it's a stunning piece. But...
Gosh, if they had cut the movie down to 80 minutes (instead of 140!!!), it would've been so much better. I mean, they fly. And fly. And fly some more. And then there's even more flying. And they walk. And walk. And walk. And then Dave flies. And flies. And flies through some weird lights. And he flies some more. And some more. Eh.
You know, I couldn't have cared less about the alien artifact. The movie dragged so much that by the end of it, I really wasn't all that interested in the thing. I would've preferred if the movie was about Dave and HAL and their battle of wills. The whole thing with HAL was over way too fast, considering how worried Dave was about disconnecting the proper bits. I think... I think that's why I consider
Prometheus to be more interesting in this regard. David vs. Elizabeth was much deeper and also broader than Dave vs. HAL. Which is too bad, really. I really would've preferred if that was the movie's main storyline, Dave vs. HAL, humanity vs. computer technology.
And the ending... I read the explanation someone posted in one of the IMDB forums, it was taken from the book by Arthur C. Clarke who wrote the novelization of this movie. But it was just his version, not Kubrick's. Kubrick refused to authorize the book. So... I really hate movies that leave the ending for people to interpret. If you have something to say, say it, don't make people guess.
To sum it up, worth seeing but... I guess I don't get why people consider this such a masterpiece. Visually? Awesome for 1968. The rest? Eh.