Lamb-Burgers

I found a great sounding recipe for a Caprese Burger from a commenter on a blog i frequently read, This Week for Dinner.
A caprese salad is usually made with slices of fresh mozzarella, tomato and basil leaves. This hamburger has all of those ingredients and it sounded fabulous, so I bought the ingredients and they turned out awesome. We grilled ciabiata rolls with the aioli (which is just a jazzed up mayo, basically) on them. I added tomato, David didn't. It was nice to have something more than the regular ketchup and mustard.

What is your favorite hamburger?