Lucy, Nora, Nell, Nan, Pippa, Dot, Bea, Lily, Meg, Dora, Tess.
I think my ranking is slightly clouded by trying to match the nickname with a romance-y first name than just plain preference of nicknames.
But, I do adore Lucy, Nora, Nell and Nan. I think Pippa and Dot are just spunky and fun. I like Beatrice/Beatrix but am not the biggest fan of Bea. The only full name I can think of for Lily is Lillian, which doesn't seem to fit your requirements and style so I think that ranking could be higher or lower if I knew the matching first name. I love Margaret, Magdalena, Magnolia but feel like Meg is so generic. Dora reminds me of the show, it shouldn't especially since I've never seen it, but it does. I just don't see the appeal of Tess.