Once upon a time, particularly during the comics code days, comic book superheroes were written to be role models for kids, upholding "truth, justice, and the American way." Over time, that got pretty boring. As comic book writers made their characters more realistic, they struggled with the moral ambiguities of fighting super villains and dealing with modern life. And sometimes those superheroes could be plain assholes.
DC superheroes in particular have been saddled with the many ethical qualities that once made them so popular, but in recent decades have been shown to be much less wholesome than they were originally portrayed. Even the poster boy for DC, Superman, has been taken through a host of changes that have marked him as something less than the ideal superhero he was touted as in the beginning. As far as lying and cheating however, Superman is still a boy scout when compared to the five heroes listed below.
Read about the DC superheroes who have made lying a part of their personalities in order to achieve their ends at Unreality.