who does the best acting in film, Sam Rockwell or Kevin Spacey?
Definitely Sam Rockwell; he did an amazing job.
I've never seen it but if you say you saw 50 times, I have to at least watch once.
Yes I recommend it; it's a slower paced movie but if you like good sci-fi, you'll enjoy it.
what is it about?
Without any spoilers, it's basically about a man who works alone on the moon at a mining facility. 
You know mining on the moon is really gonna take off 2025
Oh really? You think so? I haven't heard anything.
it will give more resources of energy and raw materials. Lots a plans for that
Yeah just like in the movie; that would be cool.