This compilation demonstrates how Mariah Carey has been one of the most maddeningly uneven pop artists of recent time. When she's good, she's really good, but when she's bad, she's awful. I would rate about half this album 5 stars, the other half just 1. I know this averages out to 3 stars, but I decided to give it a fourth star because I like the good songs so much.
At her core, Mariah is basically a torch singer. She is at her best on smoky ballads like "My All" and "I don't Wanna Cry," on which she uses the lower end of her incredible vocal range. Mariah is also very good in a duet setting, when she gets to play off a contrasting voice. "When you Believe" (with Whitney Houston), "Whenever You Call" (with Brian McKnight), and "One Sweet Day" (with Boyz II Men) are all made interesting by the interplay between singers.
On the down side, Mariah is unconvincing as a soul singer (e.g., "Honey"), and her attempts at hip hop are embarrassingly weak (e.g., "Sweetheart"). Even her good songs teeter on the brink of sugary banality, and some are just too treacly for my taste (e.g., "Hero").
If you like Mariah's hits and want to own just one of her albums, I recommend this one. Just be prepared to skip over some of the tracks when you play it.