Loved him in his first story as The General in JLA, and again when he came back for the Injustice Gang arc. And then I saw him in Salvation Run just kind of idly standing in the background here and there disappointingly (part of the Suicide Squad if memory serves). Dude is a great tactician and has the power to slap around the Justice League, but it seems as if all that most writers can think to do with him are cameos. So someone with his kind of power was actually free and running around without trying to pick a fight with the League? At least throw him in space or the phantom zone or something, so we have a reason for why he hasn't made a big splash anywhere (pre DCnU).
Still, J.K. Simmons was awesome as his voice in the cartoon.