I use the Sony VTC6, as well as the Samsung 30Q. The VTC6 are slightly better cells. Their internal resistance is lower, and they have a bit less voltage sag. They also have about 4% more energy. But, overall, they’re very similar to the 30Q, and you’d probably not notice any difference.
I also like the Sanyo GA cells. They’re 3500mAh cells, though not as high drain. 10 amps max, compared to 15 amps for the 30Q. Unless you have a light that requires high-drain, the GA cells will run your lights noticeably longer. It’s great for any single-emitter 1x18650 light.