The most classic hearts are, of course, the Swarovski Crystal heart pendants! I have a few colors available in my shops: Vitrail Light and a Blue/Purple/Pink set:
I also have a lot of bling bling heart shaped rhinestone charms. I am sure you'll find one you like!
Here are a couple fun charms with hearts and fun heart shaped findings!
My absolute favorite heart item right now are these rock/punkish silver heart with wings pendant. It's like love with an attitude. There are a lot more heart items in my shop! Be sure to take a look there!