In our new and improved household, the boyfriend and I both do the cooking.
Since we have opposite days off, we each basically do the planning/shopping/cooking of supper on our days off. (and just FYI, it was totally his idea!)
We have different ideas about how to do it, of course. I'm more in the plan-ahead-and-buy-all-the-groceries-you-need-for-several-days camp, while he's from the go-to-the-store-every-day-and-figure-out-the-menu-while-you're-shopping school of thought. Both ways work, of course. And a bonus with his plan is getting a little walk out of the deal also, if we go to the store that's only a block away. (although they are probably higher priced on some things than the bag it yourself store, and you can't buy in bulk if you're walking)
The other difference is cooking style, he used to be the bachelor chef, where I was the single-mom cook, cooking kid stuff, and eating cheese and crackers myself.
It's fun this way, we challenge each other. Of course, we both still have the basic burger-helper type meals, but we're both trying to out do each other with new food ideas.