Country and country rock, folk rock, blues rock, all kinds of jazz, classic rock, AOR/soft rock/yacht rock, prog, classical (and especially opera, if you don't count that as a separate genre), funk, synth-pop (Orchestral Manoeuvres in the Dark for the win!), jam bands, singer-songwriters (Jim Croce, Gordon Lightfoot, Al Stewart, Carole King), folk music (mainly from the Isles), Latin pop/rock, corridos, Latin jazz, movie soundtracks, baroque pop, hip hop, mbaqanga, crooners, big band, whatever Mike Oldfield is...
In fact, lately, I have been only very rarely listening to metal - I sometimes come back to Maiden or Dream Theater or Symph X or Angra or Blind Guardian (and I'm really looking forward to participating in the Devin Discussion Survivor, but in general it's a rather small percentage of the music I listen to.
However, which one of the above is the most "opposite" genre you'll have to pick for yourself, because I honestly don't know.