Originally Posted by Fat EvilMario
I've been finding Terrakion a bit disappointing. He has so many common weaknesses that anything he can't OHKO spells doom for him. I've been using Fighting Gem over Life Orb though, so maybe once I switch it over, he'll produce a bit more.
One of the more unique and successful sets I've see is a Substitute-Disable Gengar. With so many physical Pokemon only likely to have one move to hit Gengar, it works quite well.
I used to use Terrakion as a sashed lead, and it worked pretty well most of the time.