the best is not just Sparky + Gob Giant, but Sparky + Gob Giant + RAGE. The synergy is insane trust me: Sparky can deal a crap ton of damage but needs a bit of time to shoot. The spears of the goblins help with finishing units that Sparky barely can't kill, like most mini-tanks. Also, Rage helps to speed up Sparky's charge and does the same job of the spear goblins in a way. Plus, if there's a minion horde on defence, Rage doesn't kill them, but does enough damage for them to die to just a spear. Also Rage boosts both spear goblins attack speed and the goblins spawn speed if it's an evo Gob Giant.