There has been talk going around about Ares being hard on your system, so for now I would steer clear of it, but for the Ripjaws X vs. Vengeance, I would lean toward G.Skill RAM just because of the reviews I've read on third party websites. But as for the best, they both have the same performance, so it depends on your specific requirements, the Vengeance has a really tall heatsync, which can be a good or bad thing depending on your case, if your case has bad airflow, having the extra heatsync may help keep your RAM at proper temperatures, but if you have a large CPU fan in a smaller MoBo, the heatsync may get in the way of your CPU cooler.