[Tiberius]

I am not to sure about "holy grail" but here is a list of figures I find VERY hard to find and usually don't go for a "fair" price on ebay. Here we go:

X-Men Origins Line:
Cyclops
Iceman [although I finally found one for 3 bucks!]
Colossus
Sabertooth and Blob pack
Wolverine on bike with Sabertooth
Colossus and Wolverine 2 pack
Movie version Deadpool.

Spider-man toyline:
Carnage [finally found him too, once, and only once since then]
Rhino [Seen twice, bought once =3]

Marvel Universe:
Flame on Human Torch
All of Thanos wave
Dr Doom and Absorbing man Comic Pack
Storm and Nightcrawler Comic Pack
Captain America and Klaw comic Pack
All of Vision wave [saw house of M spider-man, passed on it. Still wanting Hasbro to make a fricking House of M Hulk...]
Ms Marvel [She was a pegwarmer back in the day, all I see now is classic ms marvel]
All of WWH wave

Thats about it