I love
Emma. As a small child, I preferred
Emily, but a couple moved in next-door with daughters
Charlotte and
Emma, and I fell in love with both names.
Emerald, Emerie,
Emmeline and
Emerson are all lovely, if you're looking for a less popular alternative.
Emma is feminine and classic, and will sound good, even when it inevitably decreases in popularity. The same applies to
Emily, I would say. These names aren't just trendy, as per
Madison.
Emma sounds great on girls and women of all ages, and it's easy to spell and pronounce.