I had my heart set on Moissanite before I even saw Asha LOL. Moissanite's sparkle is just INCREDIBLE.
BUT - I am not trying to pass my ring off as a diamond (even though to most anyone I TOTALLY could!!!) - I've heard from the other ladies on this board that if you want it to look as close to diamond as you can - go Asha (but I've heard that Ashas can crack or chip or something - not as strong as Moissanite) and if you want the durability and the added fire, go Moissanite.
I definitely needed the durability and I just fell in love with the fire and warmth of Moissanite