Movie Recommendation: Should I trust IMDb?

Hi there, nice comments about the top 12 secret shortcuts of Dataiku DSS convinced me to write another one: this time it's about plugins, movies, APIs, and how to choose the best one to watch with friends. A friend of mine has a list of all her DVDs (and takes note of who borrowed what;-). How do I choose the top 5 movies I'd like to borrow? I'm not a movie maniac and I don't know most of the titles of her collection. And when I do know one, it's most often because I have already seen it (and would prefer to watch a new one).