Which laptops had the longest battery life this year?

Presented here are the top five 2011 laptops for battery life, as measured by our in-house video playback battery drain test. It's easy to guess that Apple makes at least one appearance on this list, but there are some surprises as well. Note that these rankings only include integrated batteries, not secondary add-on slice batteries. If we included those, systems such as Sony's Vaio Z, with a combined 634 minutes between its internal battery and a $150 add-on slice battery together, would make the list.