I like Gentoo because it has reliable documentation, a pretty big user base, customizability, and the only way to have a Linux with the highest level of optimization. (currently)
I started from a Windows user to a Gentoo user right away. It isn't too hard to learn, as long as you have enough patience and a spare computer to help you on the way.
If you don't want to delve into Linux with the trouble of picking components, try a LiveCD/LiveDVD from one of the distributions. The highest quality of LiveCD/LiveDVD that I've come across is Sabayon - formerly known as RR4/RR64.
But... if you like a linux distro that has an interface like Windows, pick something like Lindows.