here's what I consider rare in my stash:

Pleasureflush
Stereo Rose
Metal Rock
Gold Deposit
So Ceylon
and at least one of the rest of the MSFs

2001 Holiday Face and Eye Palettes
2002 Holiday Face, Eye, and Lip Palettes
2003 Holiday Palettes Face 8 and Pink Eyes
2004 Holiday Palettes Gem, Crystal, Jewel, and Sparkle
2005 Holiday Palettes Warm, Cool, Trend, Luxuries, and Indulgences
Temperley Palette
Y & K Palette, Kei Lipglass
just got Zandra Palette, Zandra gloss and lipstick
all Nordstrom exclusive palettes from Anniversary sales
Liza PM Quad
Liza AM Quad
Perverted Pearl Quad
Denim Dish 1 and 2 Quads
and about 15 other quads....

I am somewhat obsessive complusive about palettes and quads. I think I have a problem!

oh and also Moth Brown, Metamorph, Pollen, Goldbit, etc. of more recently DC'ed shadows

theres probably more that I can't think of right now.