Queen dio(too awesome and expensive)
Aliens dio (hard to get, took me ova a year to track one down)
Alien3 dio(hard to get and awesome)
HT Supes(too awesome)
HT T1 T800(too awesome)
I guess it would have to be the pieces that use original molds. Mainly the Giger, SWS and ADI pieces I have. I have SDS stormie armor as well but that is actually for sale.
P1 life size bust. What I ended up paying for it I might as well consider a gift from the seller. He spent so much on shipping he barely broke even from when he first bought it directly from sideshow. That bust was and still is my grail of all grails.