I've been thinking about how DC could have reinvented the DCU that wouldn't have pissed me off so much.
They could have created another universe in the multiverses and started over. They could have taken the new versions of the old characters in any direction. Everything would have been new and fresh and could've been exciting. The old DCU would exist in the universe we all knew and loved, but we just wouldn't be reading about them, until/unless there was a crossing of the universes and they all met. Fun times! Same as when Earth-1 and Earth-2 characters learned about each other.
Age the longstanding DCU characters to something resembling their actual age, maybe add in a decade or two. Most would be retired, some even deceased perhaps. Keep some of the newer, younger characters in their roles, either at their age at the end of the DCU or a bit more mature. Fill out the character roster with new heroes. Maybe Bruce Wayne, Jr. is Batman. Superman and Supergirl likely age more slowly, so might be able to maintain their roles, or perhaps, their offspring have taken over.
I like either of the above options because they maintain continuity, in a fashion, and the legacy aspect of the DCU that made it so special to me for 50 plus years, along with the multiverse. The DCnU doesn't feel special at all. It just feels like a mess.