I'm sorry if this topic has been done. I couldn't find it using the search function.

Through all 3 movies and even the novel if you want to include it, who do you think was the Corleone Family's most dangerous enemy?

I think it's close between Virgil "The Turk" Sollozzo and Barzini. I would go with Sollozzo just because he almost got Don Corleone on two occasions, but he was unlucky both times. On first attempted hit, his button men should have killed the Don with those 5 shots but didn't. On second attempted hit, Michael just happened to stop by to visit his father at the right time or else Sollozzo's men would have got Don Corleone.

I know Barzini came up with the plot to get Sonny, but Sollozzo was much closer to beating the Corleone Family then anyone I can think of.