RAM is important when it comes to things such as video-editing, but when it comes to gaming - as long as your PC has a minimum of 4GB DDR3 - it's not going to give a noticeable amount of improvement. Even the speed of your RAM doesn't have much effect when playing games, and while some believe the more GB in your machine, the more FPS you'll get, the difference between having 4, 8, or 16GB has been proved to be negligible at best. Unless you're building a future-proof mega PC that could make Avatar, the only things to consider when buying your RAM is its reliability, the size of it in order to fit into your rig (low profile can be helpful), and, if you're all about the aesthetics, getting it in a colour that matches your other components.