So seriously what do you consider "rare" ?
I consider "rare" difficult to obtain and highly in demand.
My list without pictures, by that definition:
Agalloch - Of Stone, Wind and Pillor CD (out of print and in very high demand)
Burzum - Hvis Lyset Tar Oss first print CD (jewel case)
Hate Forest - Darkness 7" (276/300)
Hate Forest - Ritual 7" (98/222)
Hate Forest - Blood & Fire 7" (lim. 500, unnumbered)
Graveland - Blood of Heroes (7" 438/1488, of the 488 copies on white vinyl)
Loits - Ei Kahetse Midagari CD (lim. 555, unnumbered)
Maudlin of the Well - Bath (out of print)
Maudlin of the Well - Leaving Your Body Map (out of print)
Negurã Bunget - 'N Crugu Bradului (Digibook lim. 1000)
Nokturnal Mortum - NeChrist DLP (298/444)
Sol Invictus - Let Us Prey (out of print)
Sol Invictus - The Killing Tide (out of print)
Waldteufel - Heimliches Deutschland DLP (not really rare, but the insert is signed and addressed to me)
Wind Through The Trees - Rising Fog (3/15) [

at MFJ]
Woods of Ypres - Against The Seasons (Demo, 94/100 2nd CDr press)
Worship - Last CD Before Doomsday (lim. 500)
Worship - Last Tape Before Doomsday (MC, demo)
Worship / Mournful Congregation - Split (7'', 151/500)
plus I have the newly issued Katatonia - Brave Murder Day Purple LP and PicLP from Northern Silence Productions. Not quite rare now, but will be someday (lim. 333 and 444 copies respectively)
MFJ said:
oh yeah, I forgot, I've got a copy of that too ;p