General use, 55watts 15amps and below per battery, the Samsung 30Q
Higher stressing (higher amps above 15amps, 55watts per battery), the Sony VTC6
General all rounder, and most popular, or used to be, the LG HG2
There really isn't much difference in the 3 major players in the 3000mah arena, the HG2 and 30Q are just about identical performance wise, the VTC6 is just as on par with the other 2, but can be wiggled up a bit more in its power output, though not suggested. The deciding factor is really price, the Sony is the most expensive, being a Sony, the Samsung and LG are better price wise, all 3 can handle 55 to 60 watts per battery, and all have similar run time, though my experience the Sony lasts longer and has a higher voltage output at lower charge, less battery sag than the HG2 and 30Q. There really is no stellar best performer in the category, just price and application you will be using them the deciding factors tbh.