Top Picks
Mac OS X - The king of innovation and ease of use. Highly stable, Mac is widely-known to be the Mercedes of OS'. You will be PLEASANTLY surprised at how easy it is to use, and just how natural it feels. The only disadvantage is that it's only officially supported on Apple computers, which are costly. The "Hackintosh" project is finding a way around this, but at least Apple hardware is rock-solid.
Linux Mint - Of all Linux varieties, Linux Mint is possibly best suited for unsavvy users. While still just as stable and flexible as other varieties of the king of open source, Linux Mint puts emphasis on visuals. Its Software Manager is a central location to find all Mint programs which have been pre-bundled into .MINT installation files.
PC-BSD - Absolutely all things just stated about Linux Mint can also be said about PC-BSD, The only difference being that this is based on FreeBSD. PC-BSD only has very, very minor kinks to work out, such as the fact that Pogo.com games didn't wanna load through Java. But given that this hard-working team is financially-backed, they'll have it worked out in no time.
Worthy Contenders
Ubuntu Linux - Being one of the most-used Linux varieties, as well as being on the user-friendly side, Ubuntu will easily be a recommendation from any Linux user.
MorphOS - If you have a PPC-based Mac Mini G4, then consider MorphOS. It's a beautifully-designed, lightning-fast operating system based on AmigaOS. It actually fully boots in 4 seconds, faster than even the upcoming Google ChromeOS. I haven't had the chance to test it out myself, but I understand that it's quite nice.
CrunchBang Linux - If you're like me, then you're poor and you have to deal with older, slower hardware. CrunchBang Linux makes the most of it by being very LIGHT on the precious small amounts of system resources that you have.
