I thought the recent Clash of the Titans remake was a great movie, but the critics hated it and none of my friends liked it.
I hated At World's End. No matter how bad On Stranger Tides may turn out to be, it can't be worse than its predecessor.
Also, if a horror movie comes out that gets universally negative reception, that's almost a guarantee that I'll love it. Friday the 13th, The Strangers, The Roommate, etc...I love bad horror movies.