Since last month I'm using Ubuntu on my laptop. Beautiful distro. Fast boot, working sleep mode and a solid desktop experience. Reasonable amount of packages, yet installing some newer applications might get bit tricky as only security and update patches are back ported. Support is on very good level and it has good momentum. Compared to Vista and Xp is offers simple but very intuitive user experience across the whole desktop. Personally all I had to do to was to enable activation of windows by moving mouse button over them. You just then hover your mouse over you music player and scroll the middle mouse button to raise/lower the volume. Use same technique for seeking movies and it works in many other areas as well. I do not know if there is any real reason why this is not default. Put it in one sentece I would say Ubuntu is just great for end users.
But I miss Gentoo. Gentoo offers unmatchable flexibility in configuration and system maintenance (at least as far as I know). Powerful tools and a large catalog of applications ready just to be plugged into the system. Yet, still very clean design and philosophy. Ideal distribution for developers, advanced system administrators and those willing to try. Unfortunately Daniel Robbins has left Gentoo a while ago and it seems, although there are many great people involved in the project, not many new great features came out of it then. Still it is one of the best advanced Linux distros out there.