which lunix distro?

I've used Slackware since 1994 but I'm looking for something that isn't such a pain in the ass.  I've learned everything I need to learn from Slackware's pain-in-the-assness, so I want to take it easy and use a more user-friendly distribution.

Is Ubuntu any good?  Fedora?  What about Mandrake?  Gentoo?

What's the difference between all the distros? Someone help out a Lunix noob.