1994>2010 as far as 'All I Want For Christmas Is You' is concerned. It annoys me that they cut the vocal slayage at the beginning of the song on the 2010 version.
Although I love the ending of 2010. "All I really want is, want is, want is"...
O Holy Night is an entire adventure with each listen. When you reach the end of the song Mariah has lifted you to the heavens, ha B6 rips through an atheist's soul like the Lord's judgement upon the devil.
Honestly I consider 1990-1996 to be one Mariah, 1997-2000 is another, 2001-2006 is another, and 2007-present as another. She just looks like completely different people in various stages of her career.