I'm pretty selective. But I like to watch a wide spectrum of films so that I remember what bad movies and mediocre movies are like relative to good ones. It helps to put things in perspective when you watch stuff like Oz and Gangster Squad.
I guess I just don't see the point in reviewing movies based off the crowd reaction. Also, an 'A' for me is The Social Network, The Dark Knight, There Will Be Blood, The Lord of the Rings trilogy, Fight Club, etc. Seminal films. So I don't get it when you give movies like Oblivion an 'A.' But like you said, if it's just based off the crowd experience, then okay.