Jupz seriously do some research. I've just zoned in on what you've said about GnW tbh. GnW's only good (ONLY) aerial is Nair. Did you know I'd rather get hit by the first hit of Bair then shield it? Its that NOT GOOD, you can DI out and hit with pretty much any attack you want. His Fair is lol, Dair is good for mindgames (and stuff) and his Uair is weird. Not sure how to rank that as an aerial.
It also appears that you need to do research about ZSS's Nair. Seriously, go do it right now. Then go play, use Nair and be amazed at how good it is. It goes through other aerials and hits, it clanks, it combos, it hits at angles that can't be punished. In short its amazing.
I'm not going to be presumptuous, ZSS isn't that good a character ok? But her air game is top class. Uair is seriously amazing, her Uair beats Kirby's Bair just for a helpful example to the folks playing at home. Fair deals 17% fresh I believe, bair is good and cancels, and Dair is.... Ok Dair sucks. A lot.
I'll go through the list of top 10 and put my spin on aerial MU's.
MK: Yeah I'm going with MK as he ***** in all directions and has Lol gimp on his Dair
Snake: Hahahahahaha no. ZSS destroys snakes Aerials, more range, safe on block. Canceling faster the list goes on. In no way is Snake's aerials better (except damage wise obviously)
Wario: Another tough one but from experience ZSS is better in almost all departments, Wario's Dair is obviously a better Dair. But ZSS has better horizontal range, Nair's weird angle, far better Uair.
Falco: I dunno but I'm still going to go with ZSS for superior range on all aerials.
Diddy: ZSS is faster, has more range, and better priority and all that. Definitely better aerials.
D3: Lol he has more range on his Dair and thats about it. They're also slow, telegraphed and the only one worth mentioning aside from Dair is Bair. Which is similar to ZSS's bair but definitely not as good as her Uair.
GnW: I've already covered this.
Marth: Weird and I'm going with marth, superior disjoints and range I believe. Sword characters make me sad
Pika: Definitely ZSS, she beats him in the air easily
Olimar: He has aerials?
Not mentioned in most of those is the fact that ZSS is a superior comboer to most of those chars (with the possible exception of MK) in the air. Her Uair links to MOAR UAIR and Nair sets up combos. Also is the fact that ZSS forces AD's a lot and punishes them. (and in the case of Uair you have to beat it straight up as I don't think it can be AD if the ZSS is doing it right)
Long story short, go play a good ZSS, or watch some videos of ZSS, or just do some research and then come back here when you know what the hell you are talking about.
kthxbai