Best 80's music is pop,disco and rock. At 80's Michael Jackson was doing really great with pop,abba was at disco music and Rock was pink floyd and others
The best 80s music is fun, up-tempo stuff that people can dance to. A great example is anything from Madonna in that era - Material Girl, Express Yourself, and Borderline come to mind.
The best I believe was anything from hip hop (public enemy & salt n pepa),punk rock (bad religio & The misfits),heavy metal (Kiss & Motley Crue), r & b (New edition) and freestyle (Lisa Lisa & cult jam).
For your 80's party here I give some songs that can be play for your party:
The Winner takes its all by Abba
American you can do magic
Barbra Streisand - Woman in Love