Why the low rating? OK, I know it's not City on the edge of forever, but Spocks Brain has got a lot going for it. There's the attractive subterranean alien girls who's only ability to be intelligent lies in putting on a big football helmet with Glowy things sticking out of it. Let's not forget the 7 foot tall cavemen with funny haircuts who live on the planet surface. And best of all, and I mean this, how great is it to see Spock being remote controlled around by Dr. McCoy?
In all seriousness, Spocks brain is not the apex of Star Trek. But it is definitely entertaining and I demand it be given a little more respect :-)