Darkness or Light? Philosophy in Knights of the Old Republic.

But still, agree that if Anakin had listened to Yoda's advice, Padme would be alive, and he would have remained on the side of the light.
By the way, selfishness and, how to put it correctly... um... madness, or something like that, well, in general, about the Sith, or rather about their egoism and desire for omnipotence:
In this very Episode III, remember what Anakin said to Padme when he met her:

Together, we will rule the galaxy!!!

Something like that.
And in general, Obi-Wan should have finished off Anakin, even though it's not very Jedi-like.
And in general, Anakin is some kind of... well, I don't know, I don't remember the type, well, in order to save his beloved, what did he do:
He killed a lot of people, including younglings, switched to the Dark Side, I personally doubt that Padme would have wanted him to do such a thing for her.

In general, you need to listen to the advice of the Jedi :D.