17. Brainiac

To be quite honest, the Man of Steel doesn't have the best gallery of rogues. Superman might be a legendary hero but his villains… not so much. But through its repeated appearances over the decades culminating in one incredible, history-altering storyline last year, one particular city-collecting cyborg has become one of our all-time favorites.

Brainiac has had multiple incarnations over the years, some consistent and some diverging radically from previous stories. Geoff Johns streamlined all of that last year, putting forth the idea that every iteration in fact originated from one master that had never been seen by fans. This original Brainiac's purpose was to capture cities and assimilate knowledge in order to gain power. Part of its operating procedure was to destroy planets and galaxies in its wake to prevent that knowledge from spreading.

As part of this reimagining, Johns also revealed that General Zod was a fierce defender of Krypton when Brainiac arrived to acquire the city of Kandor, adding layers to a character that prior to Johns' involvement was a stereotypical megalomaniac. Beyond his implications for other villains and his legacy within Superman's rogues, Brainiac's most important traits are these - it has a very personal connection to Kal-El and can directly challenge him both physically and mentally. There are very few that have that distinction, allowing Brainiac to rank up there with the best of them.