Well as an avid Tamla fan

there is so much to choose from throughout the golden era i.e. prior to Berry Gordy taking what he wanted from Detroit down to to LA, never to be the same musical powerhouse again.
Nevertheless, I think my choice would have to be 'Someday we'll be together', by Dianne Ross and the Supremes. Everything about it is Motown, **Diana Ross's great voice, great song, the strong motown rythmn and string arrangements, makes it the perfect Motown sound. So here it is for those of you unaware of this classic
http://www.youtube.com/watch?v=HXGz8i0I2L0.
A couple of interesting facts about this record. It was produced and co-written by the great Johnny 'Hang on in there baby' Bristol. It is Johnny Bristol that you can hear 'harmonising' with Ross. It was not meant to be part of the production at all, but Britol helping Ross to get to where he wanted her voice to be. And the legend goes that Berry Gordy (owner and creator of Tamla Motown,and the then Mr Diana Ross) heard this overlay to the track and kept the Britol harmonies in the final release as they added so much to the production. Although the last released single of Diana Ross and the Supreme, the production did not include any participation from any other members of the Supremes.
There you go another 'anal' contribution from Mr Tickets:D
** By the way can't stand this woman, but what a voice....