Close Grip Curl Bar Curls
My apologies for trying to stare into your soul! I was form checking in the camera picture.
The biceps is made of two different muscles (hence the BI in biceps.) In order to get a fully developed bicep it's important to work multiple angles. That way the muscle is always looking good no matter how you're flexing it!
When doing this lift, keep your elbows pinned near your sides, they're going to want to chicken wing themselves out to the side. Keep the elbows pinned and lift the weight in front of you to keep the weight focused on the bicep!