I prefer
Gabriella.
Gabrielle sounds masculine to me, like
Gabriel (which is pronounced gahv-ree-EL here, really similar to
Gabrielle). I am one of the people who like the nn
Gabby, so it isn't a problem- it has potential to sound awfully cute. And as I don't like
Gabrielle itself that much, I prefer it as a mn. It's also easier to find something that flows.
Titania GabriellePetra GabrielleCassiopeia GabrielleAmarantha GabrielleBettina GabrielleClarissa GabrielleAnina GabrielleOphelia GabrielleCristina GabrielleRebecca GabrielleRosetta GabrielleRoxana GabrielleSabina GabrielleSusannah Gabrielle
Some of these can be reversed, if you like.