Audio/Video Playback and Authoring
If you're into iTunes or Windows Media Player, give Amarok or VLC a spin. Your Linux distribution probably comes with a choice of music players, but the one that most closely matches the features of the leading Windows players is Amarok. As in iTunes (or Windows Media Player or Winamp), you can build a library of music, play CDs, create playlists, copy songs to your portable MP3 player, and stream online stations, including Last.fm.
Ripping CDs to your Amarok library requires a bit of Konquerer drag-and-drop sleight of hand, or you can simply use the excellent Sound Juicer or Grip rippers included with your Linux distribution. Amarok even incorporates an online music store, albeit one devoid of major-label artists.
Amarok doesn't do video, unfortunately. Another excellent free player, VLC, offers a compact, uncluttered interface and plays just about any video or audio file type you throw at it, including streaming video and audio, DVDs, and CDs.
Instead of Nero, use K3B. Nero 8 Ultra Edition does it all--ripping, burning, authoring, backing up, and more, to both CDs and DVDs. K3B nearly matches Nero's prowess, allowing you to rip or copy CDs and DVDs, format and erase rewritable DVDs and CDs, burn CD and DVD .iso image files to disc, and create audio CDs, video DVDs, and data discs in both formats.
Replace Windows Media Center with MythTV. Wish you could build your own Linux-based digital video recorder like the one in Windows Media Center? MythTV does the job, supporting a number of popular video-capture cards (including HDTV versions) and remote controls.
Installing and configuring MythTV is not for Linux newbies, however. You can sidestep much of the process by downloading and installing Mythbuntu, a Ubuntu Linux variant that comes with MythTV preinstalled.