What\'s the most important measure of any laptop? Some might say the processor speed, or the size and weight, but at the end of the day, it\'s got to be battery life. After all, these are mobile devices, designed to be used in coffee shops, airport lounges, and college libraries (even big laptops get carted around occasionally), so being able to spend the maximum amount of time possible away from a wall outlet is important. During 2011, the CNET Labs team tested more than 100 laptops, from 11-inch ultraportables to monster 18-inch gaming rigs. Despite the wide range of laptop prices, components, and designs, battery life is better than ever across the board, thanks in part to Intel\'s current generation of power-efficient CPUs. Only a handful of systems this year had batteries that were deemed unacceptably short-lived. 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. Click through to the gallery to see the top five longest battery life laptops of 2011, then in the comments section below, let us know why battery life is, or is not, your most important factor in picking a laptop.