I know good. I watch and figure out good/bad for myself. I've seen enough film, heard enough music and played enough games to have a wide enough selection of influence to draw from. I'm same way about food. I am a bit of a snob, but I don't blog about it or hype things because I know my taste is far removed from others' taste. I rarely ever seek out someone else's opinion because I honestly don't trust many people's opinion.
A movie thread goes like this for me: Before release, I check out the trailer in the OP and ignore most of the thread. If I eventually see it and I have some angles or theories on the film, I will come into the thread to discuss those ideas and see if those ideas have been discussed. Normally, most can't follow where I am going and would rather discuss some actresses's facial expression. So I leave the thread because they're dumbfucks. The End.