Necron Tie Fighter!
I did not do this, but may very well have to take some inspiration from it. This is awesome. Granted, based on the bits I see in there, this model probably cost $200 or so in conversion parts. I see at the very least a box of Wraiths, a Monolith an Annihilation Barge and leftover bits from some Grey Knight guns.
I'm not sure who did this, but there were some other photos google found from the same guy in a random forum post somewhere.