Linux.com

Check out these websites: http://polishlinux.org/choose/quiz/ http://www.zegeniestudios.net/ldc/ After you take the quizzes, research the distros that they suggested, and burn some livecd's.

Pretty much all the Linux distros will handle multimedia, though many require some configuration after installation due to the proprietary nature of many media codecs. Often this is not difficult, but a distro that comes pre-configured with the needed codecs and software is helpful (easy out-of-the-box). For a fast system which plays most of what you'll likely want, try Puppy. For a full system with all the bells and whistles, try Mint or SAM (or the other majors + adjustments). For an intermediate weight, try Zenwalk. If you have creative goals, try ArtistX, Ubuntu Studio or Musix. Good luck!