Most of my favorites are from Vanishing Cabinets because I have A Thing about subs, and some others have been discontinued, and then there's the whole limited edition thing, but from the ones currently available:
Goblet of Red
It Can't Rain All the Time
Degrees of Death and Virtue
And this is where I realize how many discontinuations of my favorites have happened! I love Hallelujah, for example, but it's DC'd.
(But my favorite NM products overall are not eyeshadows. Their lip balm is my current favorite lip balm, period, although there seems to have been a period where they had a formula I didn't care for. It was the formulation of Coffin Kissers right before they changed to Night Kiss or whatever they're called now. And their matte liquid lipstick! I've tried two of them so far, and both of them seem to be a formula that really works for me, so I have two more -- in a double-ended tube -- that just arrived today and haven't really been worn yet.)