I didn't pay a lot of attention to reviews of Cloud Atlas when it was released in theatres, but I got the general impression that it might be both pretentious and incomprehensible. So I was pleasantly surprised to find that—after initial disorientation and confusion—eventually things made sense and I was able to enjoy myself. And (it turns out) part of the fun is trying to straighten things out and notice connecting threads. Yes, there's some goofy metaphysical bullshit involved along the way, but it's easy to ignore, and didn't stop me from having a good time.
The movie presents six stories (and a short bracketing prologue and epilogue) each set in a different era. The segments differ widely in tone and content: a historical 1840s morality play involving a South Seas voyage; a soap opera involving a gay composer in the 1930s; a 1970s thriller involving corporate malfeasance and a crusading reporter; a present-day dark comedy about a rest home that doubles as a prison for inconvenient oldsters; an SF saga about a rebellious clone fighting an oppressive society; and a post-apocalyptic tale about a society divided into near-savage tribes and a technologically-savvy remnant.
Many of the actors (Tom Hanks, Halle Berry, Jim Broadbent, Hugo Weaving, Jim Sturgess, Doona Bae, Hugh Grant,…) appear as different (but connected!) characters in each yarn. (Thanks to heavy use of makeup, hair stylists, and prosthetics, they're often difficult to recognize.)
It's long (nearly three hours). It flopped in theatrical release. The primary moviemakers are the Wachowski, erm, siblings, best known for The Matrix. I think it's probably the best thing they've done since then.