My brother plays Nids, and I can usually take him down. He plays a swarm list with some Dakka Fexes and a Winged Tyrant. This is my standard 1750 List.

300 - The Deceiver
200 - Necron Lord w/ Orb and VoD
198 - 11 Necron Warriors
180 - 10 Necron Warriors
280 - 10 Immortals
235 - Monolith
200 - 4 Destroyers
150 - 3 Destroyers

I know it's a boring list, but this is my competitive list. If played right, I don't have to worry about phase out.

Against a swarm army, the Monolith using its Flux Arc, the Immortals and the Destroyers can usually lay down enough firepower to wipe out troops and warriors easily, while being mobile enough to keep a good distance.

Against a Ziilla list, I'll send the Deceiver out to just FSU, seriously, he tears MC's apart.

It works for me.