Actually, come to think of it, doesn't Doctor Manhattan become the quantum observer of an infinite number of possible histories of the universe, collapsing them all into a singular reality only by acting backwards through time to cause the accident which gave him his powers in the first place (at least according to Straczynski's Before Watchman)?
On this Earth, Sharon Carter failed to destroy Doom's device, allowing the Red Skull to retrieve Steve Roger's body from the time-stream and inhabit it. However, as Bucky has thwarted the Third Party plot, the Skull takes an alternate approach, running for president himself as the "miraculously resurrected" Steve Rogers on the platform of repealing the Super-Hero Registration Act. His facade as a martyr and messiah figure allow him to easily win the election, but upon taking office he appears reluctant to repeal the law as promised. Instead, the Red Skull utilizes the Fifty State Initiative to turn all registered heroes into his own personal army of storm troopers. Under his rule, America becomes increasingly fascist, with Skull managing to avoid serious criticism of his administration by means of the good will accumulated by Rogers in life and the religious zeal surrounding his return. Eventually, however, Tony Stark as head of S.H.I.E.L.D. discovers evidence of the truth, and leads a coup d'état, leading to a second Super-hero Civil War. In the final battle Tony Stark and "Steve Rogers" confront each other once again, killing one another in an epic showdown, but leaving America in ruins and flame.
The most intelligent comic, the most profound, the most meta, the most emotionally compelling, and unfortunately, the most underrated, is Grant Morrison's Flex Mentallo: Man of Muscle Mystery. I just re-read it two nights ago and it continues to hold up as the greatest comic I've ever read, and stands right alongside my other favorite literary works (Milton's Paradise Lost, Spencer's sonnets, Keat's odes, Macdonald's Phantastes,Tolkien's Tree and Leaf, Lewis' Narniad, Nabokov's Lolita, and Asimov's The Last Question).
One of the Green Lanterns violate the sovereignty of an Earth nation by apprehending an intergalactic criminal whom said country tries to protect through diplomatic immunity, raising the issue of where the Green Lantern Corp. derives its jurisdiction over Earth and leading an alliance of nations (America, Atlantis, Markovia, Themiscyra, and possible others) to formally succeed from Space Sector 2814. Fearing the precedent set by rebellion would lead to anarchy throughout the universe, the Guardians send an army of Lanterns to secure the Earth. The Justice League treats such as a hostile alien invasion, and the result becomes...
My favorite origin story for any character is actually Phillip J. Fry's in Futurama. It's a temporally closed-loop, meaning that events in the future cause certain other events in the past, which lead to the aforementioned events in the future, which lead to said events in the past, and so on and so on, ad infinitum. Ignoring the part where he's his own grandfather, in a separate time-traveling escapade he goes back to the moment in which he was frozen for a thousand years, intending to alter the course of known history and recover the life in the 21st century which was stolen from him, but in a truly tragic turn at the last moment sacrifices his own happiness to preserve the time-stream, pushing his past self into the cryogenic freezer. Thus his own future sacrifice is his origin story.
I've been a comic book reader all of my life, and am greatly familiar with most mainstream characters, but cannot think of an example of which the hero's origin is a closed-loop. Could anyone provide an example of such, if it exists? As a metaphysician with a focus on the nature of time and eternity, this is of particular interest to me.
Edit: Oh, I am aware of Barry Allen being the bolt of lightning that struck his lab per Flash: Rebirth and of Myxlptlk and all other 5th dimensional beings having closed-loop timelines per Morrison's New 52 run on Action Comics. Are there any more?
I'd prefer the Sentry (as he's more of a direct analogue to Superman and would fit into the Marvel Cinematic Universe more easily), but would be willing to take a Marvelman/Miracleman movie as a second choice. If DC can't get Superman right on film (anymore; the first Chris Reeve movie is tied with the original Star Wars for greatest film of all time) then hopefully Marvel can.