Superman V (1991)
check out this crude but awesome manip :
https://s26.postimg.io/56eg28y9j/superman_v.jpg
really brings home what couldve been done for a 5th film summer of 1991 (before Batman Returns so couldve maybe piggybacked onto the success and darkness of Burtons Batman and provide Brainiac as a real threat even worse than Zod - 'Superman Into Darkness' with Peter Weller )
with salkind acquiring the rights once again and getting Donner back to 'reboot' Superman somewhat in light of the success of batman and giving the film a big budget/big stars but retaining Reeve in the central role with maybe just cameos from the regulars (as opposed to starting over and recasting everyone). Weller wouldve been a pretty big name at the time due to Robocop. i imagine M Douglas couldve been a Warfield type (Morgan Edge?) taking over the DP from Perry White and presenting a workplace challenge for Clark, Lois and Jimmy - not so much a villain as Warfield though. Clint Eastwood couldve been a Police Chief (Commissioner Henderson?)or Army general type doing battle with Brainiac. Kidder couldve had a cameo as Lois with Annette O Toole being the main love interest again as in III and maybe also a younger actress like Sharon Stone or Rene Russo as a Cat Grant type to play opposite the 40 year old Reeve (he probably wouldve looked the most Superman in V out of all the movies), Hackman as Lex in an extended cameo taking a backseat to Brainiac. Maybe even work in Stamp in a cameo as an imprisoned depowered Zod who Superman visits to discuss Brainiac. (recreates his 'you will bow down to me..' speech as Supes leaves... ) Plus brando as Jor el (voice) in a poignant Superman Returns style appearance talking to Reeve. And dont forget Williams coming back to do the entire score (lots of new material)
basically rejuvenating the series (as opposed to rebooting with a new superman/cast) in the light of the success of Batman in 89 - mixing old with new (like IV tried to do but on a much grander scale) making it a real event film and surrounding Reeve with A list stars again as in the 1978 original