How Can I Be Sure. This is the original.Covered by a few people such as Dusty Springfield and Helen Reddy.These versions are okay,but I prefer then original. https://www.youtube.com/watch?v=TuKeSUUK-A4
Original: https://www.youtube.com/watch?v=zs5OfDzYqL0 Cover: https://www.youtube.com/watch?v=O7DeKnKSlUg To be honest the original was so great that I can't say the cover is better, but I think it brings a haunting quality to the lyrics which is very powerful.
How about this one? Written in 1964 for Nina Simone, by Bennie Benjamin, Gloria Caldwell, and Sol Marcus it failed to hit the charts but was was turned into a hit by Eric Burdon and the Animals and is ranked number 322 on the list of 500 greatest songs of all time by Rolling Stone. The original: http://youtu.be/9ckv6-yhnIY The Animal's version: http://youtu.be/mfwN0X8YnWo Then we have Santa Esmeralda's "disco" version which is also pretty good: http://youtu.be/Cg9qnHO_GOI