8. Reed Richards And Susan Storm
In a suitably infamous moment, the panel of Mister Fantastic slapping his wife is a pretty good symbol of their sketchy relationship. While the slap was ironically a quasi-justifiable action - as Sue was under mind control and needed to hate Reed to break out of it - the fact is that there were a series of other ways to accomplish this instead of immediately decided to slap your supposedly beloved wife.
Worse than this, though, is something more difficult to document, in the way Reed treats his wife all the time.
Sue is seldom updated on his often dangerous plans - which wouldn't necessarily be a big deal, if not for the fact they often place the lives of Reed, Sue, and their children at risk - and Sue tends to only discover this when her husband decides it suits him.
Being a married couple who are also superheroes is a scenario that would never be easy, but Mister Fantastic's passion for science often leaves him neglecting if not outright endangering his spouse and family, which isn't really okay.