It cuts down on EVERYONE having your same name (a problem when you're named MELISSA)
It puts forth a strong and proud Jewish identity.
Hebrew and English names would be the same, and you wouldn't come across "Davida Emmanuela" (my sister's Hebrew name) type issues.
These are the ones that I like the most that I'm considering for my children.
Aviva (too close to Aviyah?)
Eliezer (Eli, pronounced "EE-lye" not "EH-lee")
When I was 13, I wanted to name my first girl "Hannah Rebecca" and have her Hebrew name be "Chanah Rivka," but then my aunt stole it for her daughter, Anna. At this point I'd rather just name my child their Hebrew name in English, but unfortunately Chanah Rivka is still taken :(