Having listened to quite a few tracks of music (free and otherwise) and tested quite a few of music playing applications, I decided to comment on those that I used the most.
This being said, what I look in a music player is organising music, scrobbling (i.e. sending track info) to Last.FM, integration with remote resources as much as possible (e.g. Jamendo, Magnatune et al.) and obvously playing music ;)
Herrie – a minimalistic CLI media player with a simple ncurses interface and is able to scrobble. So far this is my favourite CLI player and quickly took over mp3blaster's role. No integration with any netlabels though.
SongBird – I used it via PortableApps when I was forced to use Windows XP on a borrowed laptop and frankly, I don't like it much. The interface is borrowed from iTunes and just doesn't work for me (or big collections in general!). On several occasions I had minute-long lags during playback and even crashes! It does have a Jamendo plugin though, but I find its behaviour odd – it opens up Jamendo's website within the player and then only plays the tracks within its own player instead of the Flash player. The huge downside is that you can only have one album in the playlist; on the other hand it does enable you to rate and comment the album directly on the website. It does sport many plugins because of XUL though and scrobbling works as well.
Rhythmbox – although the interface is very much not to my liking, I was happy to switch to it from SongBird when I got myself an Ubuntu LiveCD (yes, I'm still laptopless! XD). Scrobbling works. Jamendo and Magnatune plugins are included (by default?) and work. There are two problems that I have with its Jamendo plugin though. Firstly, the plugn is handled as separate collection and you cannot mix online tracks with those on your local collection. And secondly, it loads the whole Jamendo music repository into the playlist and then you can only filter through it using the iTunes-esque system.
Amarok 1.x – Scrobbling works. Interface is OK and is very powerful when it comes to organising (especially huge) collections. Jamendo support is missing, but Magnatune is there. Plugins to add other remote resources also exist. Mixing the remote tracks with local ones was possible.
Amarok 2.x – I absolutely adore this player! The interface is amazing with tons of extra information at hand. In the latest release both the interface and the playlist info can be pimped out to the maximum. Scrobbling, of course works. What I particularly love about it, is that it doesn't differentiate a remote from a local collection – meaning that I can simply combine tracks from my HDD with those on Ampache, Jamendo, Magnatune, Free Music Charts, Last.FM recomendations and even streams and "podcasts" in the same playlist. The Jamendo plugin is not the best yet though – it could use some spit and polish to come at least on par with the Last.FM plugin.
In my time I've used other players as well (Juk, XMMP and its clones, etc.), but that has been so long ago that I won't bother spilling pixels over them…
hook out → @faculty & birthdaying some more …"die mauer muß weg!" …oops, have to run I'll miss the lectures otherwise!