In May 2006, DC Comics had a few crossover events and special editions. For instance, there might have been new installments in ongoing series that had significant plot twists or character developments. Also, some limited series or one-shots might have come out during this month.
May 2006 saw DC Comics release a bunch of exciting stuff. Maybe there were new villains introduced or old ones making a comeback. There could have been team-up stories or standalone tales that caught the attention of fans. It's hard to pin down specific ones without looking at detailed records, but it was a month full of comic goodness.