Ok, let me do this too. According to my lastfm:
1. Greatest Hits (417)
2. The Emancipation of Mimi (259)
3. Butterfly (251)
4. Daydream (180)
5. E=MC2 (165)
Let me explain a bit why GH is first
Well, the thing is that Mariah is not very popular where I live. I knew like 5 of her songs. So, as I usually do with "old" artists I want to get in, I downloaded this GH album as it had more songs that #1's and was more recent. I played the album a lot, in the bathroom while showering etc.
The thing is that, as it usually happens to me, I started liking a few songs, but after each play there where more songs I liked, until the end when I love just every song on the album. So what did I do after that? Obviously
free
downloading her full discography and watching her videography on Youtube. I was amazed with every album that I started to stan hard and I bought her 14 albums this last summer.
Mariah, ha real power!
I Wish You Knew 
. MIAM's weakest is probably Thirsty or One More Try and those are good songs.
I go periods where I'll just drop everything and listen to her but it's usually her 00s stuff, but I listened to the entire Daydream album and it's nearly a masterpiece