Cog is, far and away, my favourite music player. File browser on the left panel, pull a folder into the right panel, it plays the files you pull into the main box. Simple! Easy! Nice! Especially since I store all my music on my non-primary drive. Cog doesn't care where I keep my music! It just deals with whatever folder I tell it to monitor.
I also have about 200 gigs of music. It's a problem, I know.
I can't find a player this simple and elegant in Ubuntu.
Amarok: doesn't handle non-primary drives very well.
Banshee: kinda good, but fussy browsing/playlist systems.
Audacious: no file browser; it also crashes whenever I try to "import" all my music.
All I want -- seriously -- is something where I can look at my MP3 folder, drag a folder onto a playlist, and have that playlist play the songs.