3 years ago: After watching the emotional range and physique he displayed in "American Psycho" I would have went with Christian Bale as my top choice. Jim Caviezel may also have been able to pull it off.
5-10 years ago: A younger Hugh Jackman would have been fine for me in this, but if I'm ever going to see him as Superman it'll have to be on the SNL spoof. Now I only associate him with saying "bub" and slicing things, what a pity Singer found him for that and not this.
15 year ago: I would've stuck with Reeve. The only problem is that the rest of the cast weren't wearing their ages very well. Marc McClure was way too old, and I don't even want to go into Margot Kidder territory on this discussion.
As for any of the rest of the pretenders to the throne:
John Haymes Newton-Had the look and the voice, but the emotional range of a brick
Gerard Christopher-not the right speech patterns, which is important as anything in my book (I mean look at how effective Keaton's voice was for Batman, it totally detracted attention from his receding hairline), and not too far above Newton in the acting department.
Dean Cain-Get me a Ralf sack on this one. The acting was just epic from this guy. Plus his face didn't look right and he had the voice timbre of a 12-year old.
If Routh sidesteps these examples we should be in for a treat, or at least a lack of embarrasment. Aside from Reeve the only good Supermen of the last umpteen years are Tim Daly and George Newbern, and they're animated. Sad, dude. Just sad.