Best burger in NoVA? Bonus points if it's near Alexandria.

I've been craving a really good burger lately and wanted to see what everyone's favorites are.

I'm specifically looking for places around Alexandria, but I'm willing to drive if it's worth it.

I've heard names like Holy Cow, Big Buns, Hangry Burger, and Chadwicks come up before, but I'd love to hear what you all think is actually the best.

What burger spot would you recommend if you could only send someone to one place?