One of the widely used Rom around the globes. Cyanogen is not just a custom ROM but more than that. It is loaded with extended capabilities. You can backup your phone through that, work in different custom images and do number of troubleshooting options. CM Developers constantly works on more unique rom. With many loaded stuff you can simply unleash the power of your device.
Right now this is one of the most widely compatible rom and works well with number of different devices and has not crashing problem. The rom is easy to install and works well on rooted devices. I had not found anything simple than this. The new edition comes loaded with a unique UI and more advance features. This new edition works well on Android 4.2 or higher devices. So if you want to have a new OS with cooler feature then you can stick with the new edition of CyanogenMod.