A ground rod where a drain needs to go
It really doesn't matter from a technical standpoint which choice you make, assuming all installations are done properly. Do whatever is easiest for your situation. "Proper installation" is key though, only use proper drainage ells to make turns, not vent ells, and do not add additional bends to get around obstacles that can be relocated. Also note that ground rods can be bent out of the way (or driven deeper as longneck suggests) without diminishing their effectiveness, just be careful to not damage the wire connection.