The old Nautilus pullover machine might be the best overall lat movement that exists.
But if you don't have access to antique strength training equipment, then the dumbbell pullover is a solid alternative. Problem is, once the dumbbell crosses over your face there's basically zero resistance in the movement. Here's how to solve that problem.
Dumbbell Pullover With Band
Adding a band increases the resistance through the movement. You'll get a similar affect as you would with the classic pullover machine.
While waiting at the DMV for my moped license renewal form, I decided to kill some time with one of my favorite childhood pastimes. No, not chewing tobacco and throwing rocks at whores. I'm talking about that crazy little word game known as Mad Libs.