We all know Vito Corleone's character, the Godfather, was the greatest Don with the strongest family. The classic mob boss. However, nobody's perfect and this post is recognizing Vito's imperfections. Whether it be his sentimental weakness for his children, or his ignorance towards the way Carlo treated Connie, in your opinion, what was Vito's greatest flaw?

Just being a remorseless criminal was his biggest flaw to me.

But he has to be otherwise there wouldn't be a movie...

I can't disagree with Enzo overall.
More specifically, Vito's biggest flaw was to underestimate his real enemy: Barzini. After the Don's Convention, he says, "Tattaglia was a pimp, alone he could never have outfought Santino...but until this day, I never realized it was Barzini all along." IMO, he should have recognized, from the beginning, that Barzini would always be his biggest threat because Barzini was #2 and wanted to be #1. So, when Sollozzo came to him with the drug deal, Vito should have seen that Barzini, not Tattaglia, was backing Sollozzo, because Barzini would have the most to gain.

Underestimating enemies seems to have been a Corleone family trait. Sonny underestimated Carlo: he should have seen that Carlo, a Sicilian, would never let Sonny's public humiliation of him go unavenged--and that his sister, Carlo's wife, was the way Carlo would move against him. Michael should have seen that Roth wouldn't willingly give up his gambling empire to Michael--and that his supposed anointing of Michael as his heir and successor was a trick.

I'm not saying I wouldn't have made the same mistakes--or worse ones. But I'm not a Mob boss. Mob bosses need to be alert to enemies 110% of the time.

i think these flaws only affected vito in his older years, as sollozza points out. when he was younger, he almost seemed ahead of everyone by ten steps.

That's true, Mr. S: he was slippin,' as Sollozzo said. Both Vito, and Michael (with Roth)let their guards down--a consequence of trying to enjoy peace or (in Michael's case) to achieve legitimacy. A mob boss who wants to survive can never let his guard down for a moment, which means he can never enjoy a peaceful moment. That's what makes Enzo's comment so true.