Laura, but I'm biased (m)
because my name is Laura. I've loved having the name growing up, even though it was super popular the year I was born (top 40). I think it holds a lot more history and class than Lauren, which is a silly trendy offshoot birthed in the 20th century. Please, stick with the original; there are so many wonderful namesakes and ties to Laura that Lauren simply can't carry, and Laura is just plain prettier.