Britney Spears - Toxic (2003)
How excited am I!? Not. Not excited. On with it.
Most of the vocals are hard to understand. Mumbling lead vocals, breathy lead and harmony, high pitched harmony, electric strings covering up some of the lines and really odd electric "auto tune" type choices around 2:40. Speaking of the electric strings, that is some really repetitive riffs. I heard something different around 1:30 which was totally unexpected and made me pay attention. Unfortunately, it didn't lead me anywhere. The 20 second breakdown between 2:20 and 2:40 doesn't sound like her voice, and (as a breakdown does) completely drops out the previously ubiquitous repetitive drum machine/guitar/string riffs in favor of odd electronic sounds.
All in all, this is not by kind of music, but I think honestly, taking that into account, it is also a bad song.