Your first two choices are pretty similar. Both are leather. The Dessin cover has a nice inner pocket if you want something like that, while Montgomery just has a plain, soft interior. I wish I could comment on color, but we haven't gotten Montgomery in that shade yet. The Dessin one is very bright.
The Color Field covers are nice (I LOVE ORANGE!!), but they DO attract dirt with the fabric cover. We've moved our demo covers around to try and prevent it, but one does have a small smudge.
Personally, I like the Montgomery ones because of the plain interior (won't be tempted to fill it with stuff that could damage the nook!) and the strap to keep it closed.
Good luck!
