Diana Ross & The Supremes - The No. 1's

You only need to bring to mind the songs: "Where Did Our Love Go", "You Can't Hurry Love", "You Keep Me Hanging On", "Baby Love"...the solo Diana Ross work isn't as near to peerless as the Supremes classics and overall I find it a pinch too smooth by comparison to say the Shangri-Las (always my benchmark for any 60s girl group stuff, no matter how removed in sound or in other respects the outfit being compared) but these are really minor quibbles.