I love rhythmbox, it is perfect for large collections of music.  There is
one feature I feel is keeping me from ditching xmms completely.  I have a
keyboard with multimedia keys on it, so I can stop, pause, and go  back and
forth in my collection, without bringing up a window.  I can get this to
work using an excellent program called "hotkeys."  Hotkeys intercepts the
extra keycodes, and executes xmms --fwd if I'm going to the next track. 
Rhythmbox doesn't have a way to run an outside program that will send the
player commands.