Nearly every South Park alignment video or chart I've read/seen it seems that fans unanimously agree that Kenny is the most morally correct, and Cartman obviously being the worst. Some fans do argue whose a better person between Stan and Kyle, as the aforementioned charts do tend to put Kyle higher than Stan and vice versa. In my opinion, I think Stan is the better person.

They are both kind equally,Kyle and Stan are great friends,Kyle is also a caring brother and Stan gave to Kip his FB friends

Generally the way i see it, kyle's morality has a more justice, prosecutory, self-righteous vibe to it, like he has strong principles and gets outraged when the world is different from those principles, and he may be more preoccupied with bad people doing bad things and trying to stop them and even punish them (especially if it's cartman).

Stan meanwhile has a more hippie libertarian vibe where he approaches things more from empathy than principle, and while he isn't a full blown pacifist, when he does use force it tends to more about preventing harm in the present, and he's definitely more forgiving and tolerant.

In short, i think kyle focuses more on the villains where stan focuses more on the victims, and kyle has stronger convictions but stan has greater compassion.

I respect kyle allot but my own sensibilities align more with stan here.

I believe that Kyle is the most moral out of the 4

Kyle is more morale than Stan

When it comes to moral I believe the order is Kenny, Stan, Kyle, Cartman in that order. Kyle is brought down by his rivalry with Cartman which can lead him to disregard anyone else even Stan himself when it comes to beating or getting rid of Cartman. Fatbeard and Douche and Turd are good examples of where his need to beat Cartman above everything else compromises his morals. He has also has shown willingness to kill people like Cartman. One thing about Kyle is that while he is a moral person, he lacks the empathy and sympathy that Stan and Kenny have and makes it come off not to far from Cartman sometimes.

Stan meanwhile while he can have his moments, They never reach the lows that Kyle often does. Some of his actions come off more accidental than actually meaning any jerkish or amoral intent, and when it does go into that territory, He tries to make amends or doesn't understand why. With Apologies to Jessie Jackson is a good example of this. Also Randy is a bit of a bad influence on Stan when it comes to such moments.

The one thing they have is common is at their most abmoral they are like the people they hate most. Kyle for Cartman, Stan for Randy