I second Ubuntu as a first choice, although the new interface is different to what went before, and isn't that flashy. If you want something flashy, then try Kubuntu, which is Ubuntu but with KDE as the User Interface. I find Debian is best as a server OS where you need to tailor it from the ground up.

Download and try both of them from a live CD.

BTW the latest Ubuntu works great on my 6 year olf Toshiba A5 laptop with only 1gb of Ram, try that with Win 7!