Same thing here. I put Godfather II which is one my all time favorites and of course I got a suggestion for Godfather III which I consider a totally stupid movie. Apart from this I got suggestions for a bunch of gangster movies. I couldn't care less about the gangster theme, it's the quality of directing, acting and dialogue that makes Godfather II great. Ironically enough Godfather III is from the same director and with the same lead actor which supports even more the point that properties similarity is not a good predictive factor in movies recommendation.