Lots of groups that made both party and heart-throb songs.
My favorite love songs: All My Life by America, Lady by Styx,Best of My Love by Eagles, Beth by Kiss, Give A Little Bit by Supertramp.
Mona Lisa by Nat "King" Cole, any ballad by Dion and the Belmonts or Frankie Valli and the Four Seasons, or Dean Martin {Double Score for Dean Martin}