Aside from the (very few) good points of Superman IV: the Quest for Peace that you guys mentioned, there is one other good scene. It's the opening scene, where Superman saves two cosmonauts from dying in a space-lab accident. After saving them, he speaks to them briefly in Russian. It's a nice touch (Superman as global citizen), and of course it connects to the themes of the Cold War and Superman speaking at the UN.
(From what I remember, the special effects in this scene aren't so hot, but the idea is a nice touch)
I'm just glad that I don't have to feel bad, any more, about actually liking all of the Superman movies for whatever reasons or not. When a guy like Michael can pull things of worth from them then so can I. Especially SUPERMAN RETURNS, which for all of it's faults, I can't turn that flick off.