7. Ashford & Simpson – "Solid"
The key to this song is not the bombastic chorus, nor its triumphant disco synths. It's in the subtle curlicues: Simpson's breathless counter-harmonies on Ashford's verse; the half-key ascension on the pre-chorus; and, especially, when the duo sings "ha-ha-ha-ha-ha-ha-hot!" It's a study in composition and chemistry, and an example of what takes a song from being great to being a lasting pop hit. Granted, songwriting powerhouses and real-life spouses Ashford and Simpson together could do no wrong, but this is a high point, a song perfect for weddings and the roller rink (and, if you're adventurous, both at the same time).