(minor witch from mercury spoilers in the links)
hmhmmm that's a hard question!! can i choose multiple favorites?? if not, then i'll just be boring and say aerial because i love how round and sleek it is.
if i can have more than one, then i also really like lfrith, which may be a bit of a cop-out answer given that aerial is based on it, but i really love the color scheme of the original!
i'm also a fan of beguir beu and would have liked to see a lot more of it during the show. i think it will be my next gunpla purchase ehehe...
and finally, guel's darilbalde because guel and also because big round. 
(side note: i'm sorry to whoever sent me an ask prior to this one, i have a notification for it but i can't view it because it is a ghost. 👻)