Strong Female Protagonist is another superhero comic which attempts to imagine superheros as realistic people, in realistic situations. Originally a webcomic, SFP is less comic-bookish than Watchmen, or stuff by Daniel Clowes (e.g. Death Ray, Patience, or David Boring). Like to Daniel Clowes's comics, it can get pretty philosophical, but the philosophy is probably closer to what you'll see in SMBC-Comics or Existential Comics. I really enjoyed SFP, and I'm looking forward to reading the webcomic!