OpenSuse, Fedora, DSL, Ubuntu, Kubuntu, Xubuntu, Mint, Feather Linux, and a few others I have tried with KDE, Gnome, XFCE, and Fluxbox as the GUI. This is the most difficult thing for the transition in my opinion - too many options. First time setup can be a nightmare if you have an unpopular piece of hardware. Nothing I have encountered in Linux that I haven't with Windows and am happy to say that after several years of using it, is still my preferred OS of choice. After my fourth BSOD (two of which were unrecoverable), I looked for an alternative years ago. Linux needs to be given a chance by anyone in the computer world (it's free for God's sake). I have found that it is much easier to get someone hooked on Linux that has never really ventured into computers. Trying to get a 5+ year user of Windows to switch is much harder to do, it's all they know and is what they are used to/feel comfortable with. What I don't miss the most are the resource-hog anti-virus/firewall programs, having to defragment monthly, having registry errors constantly plague the overall speed/stability of the system, daily restarts, a rip-off price for an office suite, and some other things not coming to my mind at the moment. The world needs to know that they have a choice, and Linux is a fine alternative at that.