Michael Corleone is regarded as one of the best fictional characters in the history of Hollywood, and for good reason. He not only had a deep personality but was also the driver of events in three of the best movies of all time. With his homburg hat, three-piece suit, and youthful looks, Michael had the appearance of a charming, law-abiding citizen but was in reality a cold-blooded gangster.
After succeeding his father Vito as head of the family in The Godfather, Michael went on to become the most powerful mob boss in the country, an idea borrowed from Al Capone's tale. His negative traits always threatened to pul him down and put a premature end to his story, but his best traits were stronger, helping him ascend to greater heights.
Quick Thinker
After the assassination attempt on his father Vito Corleone, Michael was the first to step up and declare his intentions to kill the culprits: Tattaglia family associate Virgil "The Turk" Sollozzo and Captain Mark McCluskey. Michael did so easily, creating one of the most rewatched scenes in The Godfather Trilogy.
Michael demonstrated his creativity by hiding a gun in the bathroom of the diner where he'd meet the two. The choice of location was also a smart one since the diner was next to a noisy railway line, hence gun sounds would be muffled. The two never saw their deaths coming. Even more impressive was that prior to the whackings, Michael had also paid a local newspaper to report McCluskey's connections to the mob so that the Corleones would get no flack for killing a law enforcement officer.
Competitive
Soon after inheriting the throne, Michael knew that the Dons of the 5 New York families would not take him seriously. He thus decided to have them all whacked at the same time during the baptism of Connie's child. With them gone, Michael was free to conduct his business in peace.
Killing the bosses of 5 families at the same time was one of the greatest power moves by any mobster in history. And Michael was right to do so since the Barzini family was already putting plans in motion to have him killed. The joint executions also boosted Michael's reputation, making him the go-to guy in America's underworld.
Business Acumen
Michael had a sharp eye for business. He moved to Nevada, a place he knew had greater cash flow, so that his crime family would never have financial problems. He even visited Cuba to forge a business partnership with Fulgencio Batista's government so that his family would conduct operations there without disturbance from law enforcement.
Michael's father Vito had been too risk-averse to ever be a successful businessman. Even though he shared in his father's vision of avoiding "dirty" businesses like drug trafficking, Michael was willing to pour more money into various industries as investments. This made him wealthier and more powerful than all other mob bosses in the country.
Non-Discriminatory
Michael rewarded and punished people equally. Even family members were not exempted. He had his brother-in-law Carlo garroted to death for his involvement in Sonny's death. Fredo conspiring against Michael was one of the worst things Vito's children did and the new Don also had him killed for that.
Since he was dealing with his kin, the Don had the option of getting out harsh punishment instead of killing the two but that would have painted him as weak. In the cutthroat world of organized crime, mob bosses need to instill a sense of fear at all times in order for they themselves to be safe too and Michael knew this.
Reformist
As a boss, Michael worked on driving his family from illegitimate businesses into legitimate ones. It took him 25 years to do it, but he eventually succeeded. He reorganized his business holdings to become the "Corleone Group", instead of the Corleone Crime Family, and handed over the crown to his nephew Vincent.
Michael had proved to be a visionary modern mob boss by doing this. Traditional mob bosses before him had opted to keep things as they were for decades, resulting in endless wars with law enforcement. During Michael's reign, organized crime participants were finally being viewed as entrepreneurs.
Religious
Michael Corleone was a very religious mob boss. He prayed and used his illegally acquired wealth to donate to the church frequently. And in one of the saddest scenes in the trilogy, he confessed numerous crimes to Cardinal Lamberto. Due to his charitable gestures to the Catholic church, he was named a Commander of the Order of St. Sebastian.
The Don's closeness to God played a part in his redemption. He felt guilty about his bloody reign and opted to become a more legitimate businessman. His attachment to religion also drove him towards a path of reconciliation, making him extend an Olive branch to his estranged wife Kay.
Hardworking
Before even becoming a mob boss, Michael had proven himself as an overachiever. He attended Dartmouth College, becoming the only member of his family to go to an institution of higher learning. He then joined the Marine Corps following the Pearl Harbor attack and was awarded the Navy Cross for his bravery on the battlefield.
These early accomplishments showed that Michael could have still been successful even if he hadn't joined the mob. That he chose a different life was all down to fate. He loved his father and had to avenge him. And in his life of crime, his hard work was still evident through the numerous community projects he engaged in.
Heroic
Michael never shied away from dangerous situations. The best example of this was when he thwarted an assassination attempt on his father at the hospital.
Michael's actions were well appreciated since Vito was a very likable Don. Anyone who saves the good guy is guaranteed to get in viewers' good books. Vito would still die, but of natural causes, making him one of the few lucky bosses to never get killed or arrested. His heroic actions also put him at the front of the line in the succession race.
Cautious
Michael faced way more threats to his life than any real-life mob boss. From Lucchesi to Roth, everyone tried to take him down. Impressively, he dodged them all, with his eventual demise not coming in a violent manner.
Michael's survival was proof of his caution. He knew there would always be danger and he anticipated it. In real life, most popular mob bosses from the early '20s to the '80s were gunned down by rivals or associates seeking to overthrow them, so Michael deserves credit for avoiding harm, despite all the pain he himself had inflicted on others.
Patient
After killing Sollozzo and McCluskey, Michael went to Sicily to hide until the heat died down. Even though he found life there boring, he patiently waited for 2 years. He was planning to stay for a few more but was forced to come back after Sonny's death.
Good things did indeed come to the man who waited as Michael quickly ascended to power after coming back to America. Lying low was a smart move for him, compared to the turncoat Nick Geraci whose eagerness to get back to the normal life made him get spotted, leading to a manhunt.