I really love the concepts of #2, 4, and 5. But I think if I went into a CD store and bought a CD based solely on its cover, I'd pick #4; the colours and effects are absolutely beautiful. A close second would be #2; I love the placement of everything, though I'm a little bit iffy about both the front and back being pretty much the same picture.
And I know this doesn't really matter, but #4 looks like an album (or at least Korean album) to me. I really can't picture #2 as a cover for a Jack's Mannequin album.
As for #1, 3, and 5... #1 is very boring to me; I think you can pull off so many crazy things with a Kanye album cover, and this one just didn't do it for me. For #3, it took me a very long time to figure out what the black thing was LOL. There is almost no contrast at all (except for that big white flash on the back cover), and it just looks really flat. #5 is super clean and smooth, but I think there could have been a liiittle bit more detail; right now it just looks like a bunch of ghosts to me haha. The shirts are cute though.
I have a feeling I know which ones are Mark's and Mike's.