Luigi is a pretty good plumber and his attacks are certainly hard to deal with, but Samus has fought stronger opponents. Luigi just wouldn’t be much of a threat against her and one good Zero laser would be enough to end things. Samus is a lot faster than Luigi and her weaponry is superior. Samus wins.
DReager1.com 
but luigi wins by doing nothing
That’s fair but in this case my money would still be on Samus with the Zero laser