Without question, the most romantic choice. Louis XIV had heart-shaped diamonds in his vast collection, and Kirsten Dunst received one onscreen as Marie Antoinette. But the style really began to shine in the early 20th century, when diamond-cutting techniques improved. Kid Rock presented a big heart to Pamela Anderson when he proposed.

1.51-carat heart-shaped diamond in 18kt white gold, Blue Nile, $8,500; 888-565-7641.