Even some of my favorite songs can affect me differently depending on the day or the mood. But there are a few that I feel like I'm hearing new every time—including Ciara's "Promise," which still turns me into a winding, grinding, falsetto-singing fool six years later.
Your Love Is My Drug, Video Games, Blue Jeans, Starships, Beez in the Trap, Primadonna, Oh No!, Itty Bitty Piggy, Beautiful, Hold it Against Me. There's probably a lot more.
Vogue,Groove Is In The Heart,Fergalicious,Bad Romance, Always Be My Baby, Rude Boy, those are the only ones I could think of off the top of my head, but there are many more.
Obviously my fave's discography. But La Differenza Tra Me E Te rises above all, already 38 weeks at #1 on my personal chart, cause I just keep playing it again and again.
Other songs that never seem to get old for me are Utada's Exodus '04 and Mariah Carey's My All.