After the great back-and-forth we had in the comments of your 'Tyranids v Necrons' article I thought I'd send you my list for an upcoming tournament.
Local meta predominantly shuns Net-lists and most net advice but I still expect to see mostly MEQ, (predominantly Grey Nights and vanilla Marines). I'll almost certainly be the only Necron player there.
It's a 1500pt game, so half what I usually play at, which made trimming damn hard. The list is designed around not spamming units (because I hate spam-lists) and having as much variety as possible.
Here it is;
Overlord - naked
Royal Court - Cryptek (Storm) x 3, Cryptek (Despair) x 2
Overlord - Warscythe, C.C.B
Royal Court - Cryptek (Destruction) x 3 (x1 Solar Pulse), Cryptek (Eternity, Chronometron), Cryptek (Transmogrification, Harp of Dissonance)
Warriors x5, Ghost Ark
Warriors x5, Ghost Ark
Destroyers x3 (Heavy x3)
Annihilation Barge, Gauss Cannon
Depending on the enemy turn 1 the Warriors will bail out of the GA's and the Royal Courts bail in (naked Overlord joins the Storm and Despair Crypteks). This gives me one long-range fire platform and one short-range demolisher platform. There are almost no melee units that can take the amount of fire that one GA and Royal Court can dish out. 10 Str4, 12 Str5, 3 Str5AP3 shots and two variable strength AP1 templates wipe out... well pretty much everything. Even MC's will be staggered by it.
The Harp of Dissonance isn't extremely efficient, although the infinite range makes it useful in odd situations, but having the Hair Metal Necron with Electric Guitar I made for it on the board makes EVERY GAME BETTER.
Wraiths and Scarabs have a primarily counter-charge/interference role but can eat a Land Raider thats stupid enough to come close or devastate light transports if I'm not particularily worried about being charged (Tau, IG).
I prefer the Gauss Cannon on the Ann. Barge over the Tesla as it gives it some more utility with the AP3 and ability to glance any vehicle.
C.C.B just does its thing sprinting around dropping Sweep Attacks on MC's or transports and generally drawing fire until it goes down in a brilliant fireball in Turn 3-4.
If I drop the 2nd Ghost Ark I could give Whip Coils and 2 pistols to the Wraiths, take another troop of Warriors, give Mind Shackle Scarabs to my Overlord and an Ether Crystal to one of those Storm Crypteks. Or drop the Ether Crystal and MSS and take a unit of Immortals instead of Warriors, use the extra ten points for something fun and silly like Gaze of Flame, Lightning Field or a Nightmare Shroud.
Not sure if its a good idea or not though, as I'd only have 3 AV13 hulls and I'm worried about the ease with which they can get singled out and popped.
On a rules related question will Ether Crystal activate if the Cryptek is in a Ghost Ark? I want to say yes but I feel like its probably a no..."
Even at 1500, that's not enough scoring, particularly if you're not attaching the Crypteks to the Warrior squads. Cryptek squads are cute, particularly the way you can combine them but they are huge targets for your opponent and not exactly the most durable things in the world (low body count means RP can simply be bypassed). I'd be looking at the effects you like the best (and personally be recommending things like Harps & Lances the most) and trim them down so they can hang out with the Warrior squads and then look to get another Troop or two. I'd be looking at leaving the Warriorsin the Arks and then getting two squads of foot Immortals (larger than the Warrior squads). Even then, two Overlords + Courts at 1500 is expensive.
Otherwise some Spyders in places of the Wraiths (not large enough) to lend support to your Scarabs and potentially allow you to run two Heavy Destroyer squads (or two Scarab squads) whilst also providing some support in close combat wouldn't be a bad move.
That being said, although this is a farewell to 5th tourney, if you have to buy much (or anything) I'd be holding off until we see what 6th is bringing exactly. The above changes are assuming you have the access, or cheap access, to such models. Again though, if you don't or there are other models, the main thing I would be looking at is expanding the Troops.