This site really surprised me. It's filled with old-school games, mainly arcade and NES, but also remakes and a few others as well. The thing is, there are no downloads or installs required, you can play them directly from this website. It was programmed using either Flash or Java, I forget which. It's not perfect, though. There is no sound in the arcade games, and the NES ones are pretty choppy (but that could be my fault for running too many programs). But if you're craving a quick and dirty fix of plenty of retro, quality games, this site is for you. There aren't ads, as far as I know.