top (cpu usage) and iotop (I/O usage)
ncmpc (music player daemon client)
alsamixer
flac, ogg, and mp3 encoding
transmission-cli
One funny cli related thing if you haven't tried it yet is to try the ascii
video output
And if you wish to ditch X and still see pictures there's fbi which uses
framebuffer
Plenty of scripts, I think incron deserves a special shout out here because
it allows you to easily monitor file system changes instantly and without
polling. And since in UNIX-likes everything is a file...
