Goro doesn't really have that much honor... He does dishonable things and works for dishonable peeps... He goes back on his word (Kitana's Centaur/Shokan peace treaty) because that dishonable warroir he obeys returns. He fights by over whealming his foe with his power and is backed up by a good couple of thousand of his race. Not to mention he himself is evil.
I don't think he belongs on the most honorable...
-Raiden (until recently)
Sub zero fights for no real reason, he has no revenge aim nor does he fight for selfness. He fights because he is asked to by Raiden and his friends, even going to other realms. In the MK4 comic he travels to the temple of the elements to make peace with Fujin and the other elemental Gods on behalf of his bro. He has a fair amount of honor its salf to say.
Raiden, until becoming dark raiden led the mortals fighting for him into battle, risking his own place in the Gods. He founded the order of the light and mentors the mortals as their teacher. Old raiden as a God had a lot of honor.
Kitana fights for her people and is a kind hearted soul. she tried to make the centaurs and Shokan be peaceful. She is somewhat too kind heart though and let her false sister Mileena live instead of killing her. She again has a fair amount of honor.
The two monks have a lot of honor cause they've been trained to. No doubting they have a lot of honor.
I'm ganna put the warriors,and wich it seems hard to understand why,i'l put it next to their names
3-nighwolf(he fought shoa kahn for his ancestors honor)
5-cyrax(he lost his soul but he was able to get it back)
7-li mei(i know,i don't like her at all,but she did a sacrifice in mkda in a chance to rescue her village,but bobo bringed her back)
8-oh common,he became a thunder god again instead of elder god and he blowed the hell out of his old form in mk:d
9-rain(well,after mk3(like always mk3,umk3 and mkt)he disapeard that means that he did that suicide misson against the extremenation squad,he refused to die for 3 reasons
1-he relized that kahn was the one who killed his papa
2-he didn't want to die in the e.s.'s hands
3-he knows that no one in mk ever die)
and the last one should be scorpian,running from hell trying to beat the one who smacked his wife and childrens
If Li Mei's MK ending was gonna be true, she'd betray her friends to fight for the Dragon King. I think that may end up being true but with him loosing instead of winning.
But except for that ending where she betrays everyone, she shows no signs of dishonor. Even if its not a true ending she has a darkness inside her that could spawn itself into something worst. Thanks to Shang and Q-chi putting her soul inside a mummy.