I saw 10.000 BC the other night. It's absolutely pants! It's cheesy but takes itself seriously so just falls flat on its face.
In my opinion (and my opinion's usually right. Except when it's wrong.) it's a rip off of Apocalypse but nowhere near as good.

You know when you go to BlockBuster and see a low budget rip off copy of the latest big movie? Like I Am Omega for I Am Legend or Transmorphers for Transformers? Well, this is the same, except this cost millions to make.
Ignore the cool looking trailers and see something else instead.