Ok, all I want to say is first off I havn't seen superman returns, but I have heared many reviews for it. So this is baised off of my assumption And mine alone. Warning, may contain some spoilers, so don't read if you don't wanna know more about my super x.
Comparing things
Background story;
Semi similar in nature that their both about outer space, however nothing alike when It comes to how they got their superpowers. The ex girlfriend (Jane? I don't remember her name, sorry) Got them from a metiorite blowing up, where as superman just always had them. Oooo interesting story. Anyway, for their background story superman was on some planet that got the shit kicked out of it because they were pussies. Where as Super ex (I'll refer to her as SX from now on) was a normal nerd, who loved this guy, then after she became all hot, and her boobs got bigger, she forgot about him. I know how that feels. Again SX wins the battle, not only because it's more original, but it's kinda touching in a way.
Special effects:
So far as I've seen of "Superman: Returns" it looks like the SFX are decent, the only thing I didn't like was the whole shooting his eye thing. However on the subject of shooting, in MSXGF she gets shot in the tits and her clothes tear. That's a little better than some quier wearing spandex getting shot in the eye.
Actors:
No offence but the guy who plays superman on "Superman Returns" looks gay. Like so gay if he sucked a golf ball through a garden hose, I wouldn't be suprised. The actors in MSXGF were ok... I didn't like the main guy, who had a big jaw, but other than that he was really good. All the chicks were pretty hot besides the wierd ass boss chick. I really didn't like the main guys best friend however.... He was like... gay, but not.... It confused me
All in all, don't waste 8 bucks (or whatever your theater charges) to go see superman. And really MSXGF isn't all that good either. Maybe if we stop going to those movies they'll either make better ones, or stop making superperson movies. 50s, 60s, and 70s, flashbacks can be cool, but sometimes not...