Über The Supremes
The Supremes basically ruled the pop charts in the 1960s and don't try to let those Beatles fans tell you otherwise. No other act on the Motown roster was as consistently brilliant on the charts or releasing such sublime pop gems. The key word here is "pop," since that's what Motown did best and that's most certainly what the juggernaut songwriting combo of Holland/Dozier/Holland did like no one before or since. There was nothing especially thought-provoking in their music, but within that glassy back-beat, aerodynamic production and Diana Ross pouring on the vocals like maple syrup, there was total perfection.