Audio only, low lighting. I like to concentrate on the music with no distractions.
Music just sounds better without distraction.

No rhyme or reason to it. Lot's of times its with some beer (Zeppelin, louder rock,etc) or wine (Phoebe Snow, Joni Mitchell,etc)...I like it all.
However, having said that...
I have had profound experiences listening to Frank Sinatra in the dark with a large tumbler of Bourbon.
No holes barred here. Whether I am singing it to myself, or at work with some ear buds, or at home doing some serious listening, I find that I just truly and genuinely enjoy music regardless of format or discrimination. My only real special joy is to listen to it live. Other than that it seems to be all good no matter. I don't really fall into one or the other category.

Nice setup you got there... That S-6000 is a really-nice unit (Does yours have the turntable on top?).
By the way, to answer the thread, I usually hate music videos (with some exceptions). I think MTV hurt the music industry in a lot of ways (especially once they started in with the reality TV crap).
audio only, but I read a book when I listen.
I like jumping up and down, half naked with a bunch of women, while listening to Björk.