Most certainly the Arty Golem. It makes neutering planets painless. Even if you want to take out the WHGPs, you can without the time consuming process if you have an Arty. It's great for those irritating AI Eyes. There's no recharge time to build wasps like the Hive Golem so in terms of neutering it is vastly superior to the Hive. It's perfect for taking down the high HP tough targets (top tier of nasties from exos...I'm looking at you.)
Much love to all the other golems especially the Teensy, more so the Armored which has won me more than one HW assault, and despite not having played with the Regenerator Golem since its changes, but I've got to stick with the Artillery Golem for the favorite.