Lat Pulldowns with Underhand Grip
Builds a stronger upper back and V shape; also helps prevent shoulder problems.
This can be done with a wide grip, palms out; or a more narrow grip, palms in; or one at a time (with tubing or pulley). As you pull down, there is a tendency to lean back; slight leaning okay, but don't use the momentum or leaning back to assist the movement, because that cheats the lats. Slowly bring the bar to your breastbone area and concentrate on using your lats to do the work. (As a side note, please don't use the behind-the-neck lat pulldown, which all too often irritates the neck and shoulder areas and really doesn't work the lats that much).
Alternates: The free weight version is the single arm dumbbell row, and the tubing version is a tubing lat pulldown. Also, chin-ups are a great alternative and can be done at "negative" chin-ups--starting in the up position with some assistance, then lowering yourself slowly on your own.