Actually, there was nothing I would have substituted for the music in Skyrim, similar to the way I played the other games, except for what I am listening to as of the day before yesterday while playing for the first time ever. Silence.
The music is part of the atmosphere and the lore. As mentioned in an earlier thread on this, or maybe even this one (can't remember), I don't want to hear some emo nasal goober screaming irrelevancies into my ear about today's issues while I'm supposed to be immersed in a world that existed somewhere around the Bronze Age if not earlier. It simply has no place and detracts from the setting.
Now if you asked me what I listened to while in the midst of Unreal Tournament...the more irony and incongruousness the better. Nothing like discount dental with a flak cannon while "How Deep is Your Love" drones on in the background, or having some joker sandwiched next to his flag by an ASMD secondary blast and a 6 missile volley while "Torn Between Two Lovers" plays on behind him.