Which is better Tyranids Necrons Tau or Chaos Space Marines

All are good at diffrent things


Tau: Great for long range but not much else

Tyranids: Great for swarming in close and personal and ripping them up


Chaos: Good all round troops well balanced for beginners


Necrons: Think you kill them they get back up! damn things don't die! They have great leadership as are robots

Overall id say necrons or tyranids. i personally prefer necrons but that is just me.