Miroirs first, Gaspard second, and Tombeau third.
My favorites from each set:
(miroirs):
-Alborada del Gracioso, Vallee des Cloches. There is something about the middle section that sounds borderline like a lamenting blues riff, but not quite there. The minor-i to major-IV is so satisfying there!
(gaspard):
-All three... Ondine is perfect (probably my favorite piece by Ravel), le Gibet hits the nail on the head for the atmosphere it creates, and Scarbo is just a monster...
(tombeau):
-Forlane and Rigaudon. B major combined with D# major reminds me of my reaction to medieval music when I was really young. I get these chills, and then repeat that section over and over again. I'd almost put the toccata up there, but it's obviously great, and the Rigaudon has these awesome melodic bits that suddenly allow the piece to fall into a major tonality when you expect minor. Ahhhh Ravel!