I've noticed no matter what I've been picking up and how good it may be I always keep returning to the following:

Burial - Untrue
Portishead - Third
Radiohead - HTTT (not my favourite or most listened to of theirs but, y'know, it's a bit dark like)
Blonde Readhead - Penny Sparkle (see above)
The Horrors - Primary Colours
Mogwai - CODY
Crystal Castles - s/t (II)
Fever Ray - s/t
F^(k Buttons - Street Horrrsing
Liars - Drum's Not Dead (recently purchased and just now finally getting what it's all about)
TNPS - Hidden

I think the least dark albums I've been listening to over and over again lately are Funeral, Swim, Takk..., and Warpaint's debut