Imdb.com. They saved my eyes from watching all kind of bs many time Playing it cool, not realizing this is post #1000 for me
Yahoo or Rotten Tomatoes - whatever the users rank there pretty much matches what I decide after watching it.
IMDB is the only way to go I have found it to be the most informative site out there for all kinds of information on movies.
I usually go to yahoo.com and search the "movies" section. I watch trailers there too, then I pick what I want to download.