I've been using Audacious as a replacement for Winamp for a couple of months now since i moved from Windows 7 to Fedora 16 and i must say i like it.
It plays every MP3, OGG or XM file i throw at it (non-free MP3 codecs required) and can be fully skinned to look exactly like Winamp. Don't be fooled though, it's not Winamp! Some of the plugins are good extensions to Audacious of which i couldn't find for Winamp.
- One difference between Audacious and Winamp: It can't be docked.
- Crossfade plugin problem: Bitrates must be the same between tracks.
- MP3 files: For some unknown reason it can't update ID3 tags and it doesn't have tabs for ID3v1 and ID3v2 (unlike Winamp).
I've used Amarok, Totem and even VLC in the past but -being used to Winamp and all- Audacious has my vote for best audio player on GNU/Linux systems.