If my memory serves me right, among others -

It occurred to me Vito and Michael were not dissimilar in their - before and after – becoming evil, ruthless, murderous crime boss

Good
Vito
  • dancing with Carmela at Carlo and Connie's wedding
  • picking up baby Santino from the playpen and rocking Santino
  • “for me, there's only my wife and son [is beautiful]” while watching the play with Genco
  • looking on distressed as sick baby Fredo is crying
  • Carmela “what a nice pear” then reaching for, holding each other's hand and kissing at the dinner table

Michael
  • perfect! host to Kay at Carlo and Connie's wedding
  • Christmas shopping with Kay
  • after “The Bells of St. Mary's” at Radio City Music Hall
  • promising show and dinner outing in the city to whining! Kay just before the garden scene with Vito
  • dancing at Anthony's party [Kay did point out Michael's “legitimization of the Corleone name” promise was past it's deadline!] but Michael was trying....
  • protecting Kay after the bedroom shooting, putting his body on the line!
  • Sicily scenes with Appollonia
  • drinks with Fredo in Havana

Bad
Vito
  • shutting Carmela out of business, starting with when he went into the bathroom and closed the door on her after receiving the bundle of guns from Clemenza
  • when Carmela asked Vito “Don't you feel well? Is your boss treating you all right?” Vito says somewhat curtly “forget it”
    Michael

Michael
[however in fairness! to Michael, what was Kay expecting?!]
  • telling Kay that he did not have Carlo killed
  • shutting the door on Kay after Kay [overstayed] visiting Anthony and Mary but Kay 'aborted' their 'son'

Ugly
It is the business they had chosen Kill or be killed