Macbeth and Lady Macbeth
I’m not saying Macbeth and Lady Macbeth aren’t perfect for each other—they are. But so were Bonnie and Clyde, and they went out pretty much the same way as the Macbeths: violently and as a result of their own hubris.
Macbeth and Lady Macbeth are a trainwreck of a couple with more combined ambition and villainy than the Legion of Doom. At first, Macbeth is like, “Eh, maybe I shouldn’t kill the king, who is also my friend,” but then Lady Macbeth is like, “REAL MEN MURDER THEIR KINGS WITHOUT HESITATION,” and Macbeth is like, “Okay, okay, true.” Together, they commit all kinds of murder until (eventually) it catches up with them.
Basically, they’re a power couple who bring out the worst in each other and die as a result.