Bartok Piano Concertos are dark, emotional, and still cutting edge (even though they are 80+ years old). This is very different from what has been mentioned so far... try before you buy :-)
if you like it, I'd recommend this recording
Another recommendation in emotional contemporary piano would be Ligeti
the youtube excerpt is from Aimard "reference" recording
Also I can't resist mentioning my favorite piano piece (actually my favorite music piece), which happens to be very emotional but not dark at all
This is Pollini playing the Arietta from Beethoven last sonata. It does not get any better than this!
I happen to love Bartok but I find that one youtube piece/clip to be a bit sparse?
It is definitely darker though...