I ask this on the sib set group but I think it’s best over here. I like both but not [name_f]Margot[/name_f] because it reminds me of Maggot 
I prefer [name_f]Margot[/name_f] so [name_f]Margo[/name_f] is closest. [name_f]Margaux[/name_f] is a faux-[name_m]French[/name_m] spelling and a luxury wine brand Chateau [name_f]Margaux[/name_f].
FYI - Tragic actress-model [name_f]Margaux[/name_f] [name_m]Hemingway[/name_m] was born [name_f]Margot[/name_f]. When she learned she was conceived on the night her parents were drinking this wine, she changed the original spelling from “[name_f]Margot[/name_f]” to “[name_f]Margaux[/name_f]” to match.
I like [name_f]Margaux[/name_f], but it’s because I’m a vinophile. I would definitely not opt for that spelling unless you’re into wine because invariably people will either make an erroneous assumption about your interests or will not be familiar with Chateau [name_f]Margaux[/name_f] and will think you’re using a made-up spelling.
I prefer [name_f]Margot[/name_f] (actually have been thinking hard about this name the past few days). Out of your choices I prefer [name_f]Margo[/name_f].
[name_f]Margot[/name_f] is my favorite, then [name_f]Margo[/name_f]. [name_f]Margaux[/name_f] looks like it’s trying too hard to be [name_m]French[/name_m], which is interesting if it’s really faux [name_m]French[/name_m].
I’m not a fan of [name_f]Margaux[/name_f] for the same reasons. I like [name_f]Margo[/name_f].
I actually go back and forth on whether or not I prefer [name_f]Margo[/name_f] or [name_f]Margot[/name_f]. I agree with you about [name_f]Margot[/name_f]'s visual similarity to “maggot”, and I suspect that if I used [name_f]Margot[/name_f] people wouldn’t pronounce the T all the time, but they would pronounce it frequently enough to annoy me. I know that [name_f]Margot[/name_f] is more authentic, but I don’t mind [name_f]Margo[/name_f] in an anglophone setting.
I have family in Bordeaux and in the urban area there is a little commune called [name_f]Margaux[/name_f] (where the vineyard Château [name_f]Margaux[/name_f] is placed), so that’s pretty much what I think of whenever I hear it.
I would go with [name_f]Margo[/name_f] (I personally love it as a nickname for [name_f]Margaret[/name_f]).
If you don’t like [name_f]Margot[/name_f] (the proper [name_m]French[/name_m] form), then I’d say [name_f]Margo[/name_f], as that’s closest to [name_f]Margot[/name_f].
As others have already said, not [name_f]Margaux[/name_f] though, as it’s faux-[name_m]French[/name_m].
One of my favorite names ever! 
I’ve gone through this same dilemma. In recent years, I threw out the possibility of [name_f]Margaux[/name_f] because it does look like it’s trying too hard and/or related to the wine (which didn’t thrill me, either). Currently, I teeter between [name_f]Margot[/name_f] and [name_f]Margo[/name_f]. [name_f]Margo[/name_f] is definitely most straightforward so there will be much less pronunciation confusion.
I am also a fan of [name_f]Margot[/name_f] and didn’t even think of Maggot but if you do then I see why there’s an issue. As [name_f]Margo[/name_f] is the closet then I would go for this but in my mind [name_f]Margot[/name_f] is the best X
I definitely prefer [name_f]Margaux[/name_f], thanks to the late [name_f]Margaux[/name_f] Hemmingway.
I prefer [name_f]Margo[/name_f] of the two.
I had no idea that [name_f]Margaux[/name_f] was made up. That’s hysterical.
So wait… in [name_m]French[/name_m] you would pronounce [name_f]Margot[/name_f] and [name_f]Margaux[/name_f] the same?
I’m really torn on this one because it feels weird leaving off the T (I never see “maggot”) but I also hate silent letters.
I agree with mischa!
I prefer [name_f]Margo[/name_f]. I never see “maggot” in [name_f]Margot[/name_f] though!
I prefer [name_f]Margot[/name_f], but if that isn’t an option for you, I’d go with [name_f]Margo[/name_f].
[name_f]Margaux[/name_f] just seems a tad pretentious to me.
It’s a gorgeous name either way!
Good luck!