What are good acoustic cover songs for a wedding?

songs like the "hey ya" cover and a couple acoustic Chris brown songs are awesome but im not fully feeling them for a wedding song. I heard an acoustic cover of a song originally sung by a female but was a male in this version. the only other thing i can remember about it was it ended with a short medley of like 2 more songs. If anyone knows the cover im taking about that would be great but I'll take other suggestions of acoustic songs or covers for my wedding.