I love the sound of music from the 50's and early 60s, right at the brink of rock and roll. 70s started punk rock, so they must receive their due credit. 80s music of most genres are fun, especially to sing with friends at the top of your lungs. The 90s had that whole melancholy thing going for it and the BEST female singer song writers like Tori Amos. Don't forget the great R&B that came from. The late 90s and the early 00s.
If held by gunpoint I would have to say 90s. Jam bands, female singer songwriters, R&B, Alternative, and more. Just so many great styles came from a time where everyone was trying to get over the "rock lobster" lifestyle.