Theme Music
I almost always play music during my games... Instrumentals and sound tracks work best, of course... some of our groups favorites include Last of the Mohicans, the Lord of the Rings trilogies, Jurassic Park, Dances with Wolves, the 13th Warrior, plus many others. Also, we really enjoy the Midnight Syndicate that's been mentioned previously, as well as Red Steel's Savage Baronies. During tavern settings, I like to play parts from video games such as Baldur's Gate and the Temple of Elemental Evil's wav. files, mixed with other stuff... the background noise really helps my players to fit into what's going on, especially when I throw in a few renaissance flute or lute numbers, acoustic folk songs, or even auld poetry readings to emulate performing minstrels or gleemen. It really sets the mood.
As for theme music for the players themselves, the closest we've really come is back in the very late 80's... one of my dear friends from school, Sean, played a bard by the name of Rubino Gemseeker, and Rubino would parody the music of the time (usually hard stuff like Metallica and Zeppelin) into songs that fit our party and the members. Some songs I remember are "We are the Hunt" (our company's name at the time), "the Berserker Song" to Led Zepp's "Immigrant Song", "Crits Happen," and of course the immortal, "Why, Why Did Our Thief Have to Die?" with apologies to Don McLean. I swear, we got more laughs hearing (and singing along) to these songs in the tavern scenes than in any dungeon or overland quest. One of the very best was "Thought I'd Warn You", a very imaginative take on the Eagle's "Hotel California". I don't remember the whole thing, but I sure wish I had copies of the lyrics... little lines like "I've been possessed and I thought I'd warn ya... Now my +2 Mace... is swinging at your face." It probably doesn't sound nearly as fun out of context, but trust me, back then we were shooting Pepsi out of our respective noses!