The best lat exercise is still the pull up. There is no doubt about that. But many of us, yours truly included, simply do not have the strength to execute a pull up properly. Hence the pull up becomes a very ugly looking bicep exercise instead.
I have been experimenting with the stiff arm pulldown as a substitute for the pull up. Both work the lats but while the pull up is more bad ass, the pulldown can be properly executed by more people. And the stiff arm pulldown can really smoke your lats like crazy.
I did 3 sets of 15-rep stiff arm pulldowns yesterday and my lats are begging me for mercy today.
If you go to the gym, just use the cable machine and get cracking like how the lady in the vid does it. If like me, you don't have access to a cable machine, you can use a resistance band instead.. Just loop it over something overhead, hold it with both hands (like you would the reigns of a horse) and pull away.