I posted these in an earlier thread, but I've fixed some things:
Superman II - I'd keep everything in Donner's version except for three minor changes and one very siginificant narrative one at the end: 1) actually film the whole hotel room revelation sequence with the gun; 2) Change Superman's callout to Zod at the Planet office BACK to "Would you care to step outside?"; 3) Restore the deleted footage of Zod & Co. being hauled off by Arctic Patrol, so as to preserve Supes' code against killing; and 4) leave the love-triangle subplot at Superman and Lois' uncertain embrace outside the destroyed/sunken Fortress - so that she knows he's Superman from then on out instead of just copping the whole thing out after two films, then cut to another shot that was deleted from the film of Clark running into a bully at the Planet office, THEN go back to Rocky at the diner and on to the final scene at the White House.
Superman III - I'd probably keep the Lana/Ricky subplot, only interweave his relationship with Lois into it somehow to create dramatic complications; in addition, Brad Wilson - whose life has pretty much gone up a dead-end street since graduating from Smallville High - would suspect that Clark and Superman are the same (based on some of the weird things he'd seen Clark do years earlier) and pose a nuisance to Clark. Also, Vaughn's character would have been Milton Fine, and Brainiac would have been the extraterrestrial A.I. he's allied with, under the pretense of being a new supercomputer that Fine has built; at the end it would be revealed that Fine is merely a robotic puppet of Brainiac (voiced by Vaughn). Pryor's involvement would have either been scaled back or removed completely, and as for the "dark Superman" subplot, I might have actually held off on that.
Superman IV - Luthor probably would have been brought back (retaining the character's established switch from land-lubber to war profiteer: "Your Uncle Lex has had nothing on his mind the past few years except for one thing - Destroy Superman!"), and the anti-nuke theme would probably have been present, but significantly watered-down; also, the "Nuclear Man" subplot would be somewhat inverted and the character significantly altered - Luthor's super-clone would START OUT as a wavy-haired super-hunk version and THEN degenerate into the original version that was deleted from the finished film, going on a misguided attempt to depose Superman that leads to Lenny nicknaming the poor shlub "Bizarro" rather than "Freako". Bizarro would be more the tragic Frankenstein figure here.
Superman V/Lives & Supergirl - Basically I would have waited until we were pretty much done with Superman before worrying about bringing in Supergirl (let alone a Superkid of any kind), and then combined the two properties into one movie; have Doomsday and Superman put each other into pine boxes in the first half, with Kara picking up the mantle in the second when a robotic Superman with a hidden agenda comes forward trying to pass himself off as the man resurrected.
