It's new school versus old school today for the battle of the best. Brenda Holloway was the first to record this song and make a hit out of it too. It's story that said Brenda hated this song and didn't want to record it and actually cried because she thought it was a bad song. Well, all I know is this was a big hit for her and you can't tell on the recording that she didn't want to sing it. I regard Brenda Holloway as one of Motown Records lost treasures. She was one of their best female singers along with Gladys Knight, and Kim Weston.
Alicia Keys did this song on her MTV Unplugged album in 2006 roughly 42 years after it's first release. She did a hell of a job with it too.
Personally I'm going with Brenda Holloway. Motown just knew how to craft a song around an artists voice. Alicia Keys did a great job and I give her extra credit because hers is live but come on Alicia just can't stack up against this legend.