When serious villains need defeating in the DC universe, you'll usually find Superman helping defeat them. Like him or hate him, it's not exactly a secret that the Man of Steel is one of the strongest superheroes in all of comic books, and that this means you're likely to be crushed like a particularly thin Rivita if you try to fight him.
But not every villain has faced a pummelling from the all-American alien. In fact, plenty of bad guys have come up against Supes several times and gotten off pretty much scot-free on every single occasion.
The reasons for managing to avoid catching Clark Kent's steel hands vary. Many villains have plans that can't be foiled by Superman just beating them up - not to mention the fact that our wonder boy is just one person, and so can't thwart every evil scheme.
Though sometimes, you can avoid ever facing the righteous fury of Superman by... just being lucky, really. Sure, these villains likely spend their every waking minute wondering if a red and blue outfit is going to appear and then flying them into the sky for a beatdown - but that kind of paranoia might be worth the bragging rights of knowing Supes never quite managed to catch you.