Let me add Outlander to the list of awesome movies that you've never heard of. Outlander came out in US theaters last Friday and having followed it for a while, I went and saw it. Now, let me come clean here, Outlander isn't a particularly good movie but it sure as Hell is a totally awesome movie. That said, I do recommend going to see it while it's still on the big screen.
Vikings versus aliens really should be all the synopsis that you need to convince you to go see it but, I guess if you want more, I can give you a brief synopsis. Earth is actually an undeveloped, abandoned seed colony for the spacefaring human race. Kainan, a man from space, crash lands his ship on Earth in viking-age Norway. Kainan soon realizes that a particularly nasty alien, called a Moorwen, had stowed aboard his ship and is now on the loose. There are subsequently a lot of spaceman/viking integration/culture-shock dynamics and eventually it becomes vikings+spaceman vs. alien monster.
Just to be clear, I keep saying that this is vikings vs. aliens because that's both what it purports to be and what it delivers phenomenally well. Outlander has cult classic written all over it.