Is, in fact, a villain. The comics/movies are actually presented from his warped alien mind and viewpoints, making him seem like a force of good when in actual fact he is causing harm to the universe... the "supervillains" he fights against are actually the good guys. Therefore, the entire franchise of Superman is an elaborate satire of Nietzsche's "Ubermensch" concept and eugenics.
This sort of relates to the phrase, "One man's hero is another man's terrorist"
Also, Ozymandias was the sort of tragic hero of Watchmen... technically making Rorscharch and co. villains.