I'll third David Xanatos.
It's true he's nowhere near the likes of Reed Richards, Doctor Doom, or The Doctor, especially when it comes to science and sorcery. What Xanatos excels in, however, is finding victory in every scenario that comes his way. When I think about 'Prep', inventions and gadgets spring to mind. But the best 'preppers', I think, are those who can manipulate other characters, not just the cosmic forces of the universe. David Xanatos is very good at manipulating others, even beings who could crush him with a thought. I briefly touched upon this earlier, but I especially love just how adaptive he is to nearly every situation he's encountered. I could see Batman besting him in combat or exposing him as a criminal, but Xanatos has proven he'd not only be prepared for this, he'd find a way to make this work in his favor. Make no mistake, there's always an opportunity for you to take advantage of, it just needs to be harnessed.
Ra's al Ghul, Vandal Savage, and Lex Luthor are all excellent DC candidates too. Hell, even the Joker ranks up there.
Don't forget, what really makes Batman an excellent strategist is the fact he has friends in high places to command.