There are a bunch of threads on the forum about batteries. IIRC the truth about them is that most auto parts store brands, including Sears-Diehard, are made by the same company, though I think Odyssey is one of the few NOT made by a major group (kind of like how Huffy makes just about every bicycle you can buy at walmart/target/sports authority though they all have different names).
Good luck with your search.
I've never heard of Continental batteries, but my plan for my next battery was going to be an X2 Power battery from Batteries Plus. They're the same as a Northstar.