Ideally I want the REAL Belle back, Kirsten Storms, but if that can't happen, here are a couple of choices I'd like to see as Isabella Black Brady...
1) Erin Torpey
Best known for her role as the original Jessica Buchanan on OLTL, Erin Torpey has the prettiness, charm, and "good girl next door" qualities to pull off the role of Marlena and John's only child. We know she can hold her own with Erika Slezak--imagine what she could bring to the table with Deidre Hall!
2) Robyn Richards
Probably the best-known Maxie from GH, Robyn Richards is a terrific younger actress and also has that "girl next door" quality required for the role of Belle. Also, it would be a nice "just desserts" situation since Kirsten Storms replaced her as Maxie.