Let's start with the necessities first:
1. You want to have a few, maybe two non-stick skillets. I recommend a large one (10 to 12) inches, and a smaller one (8 to 10 inches). On top of that, you want to have a cast iron pan. A medium size should do, plus they are heavy so you would not want one larger than that. They are great for finishing up the final touches on a yummy steak!
2. A sauce pan is important, I have two in my household and I use them quite often. They are perfect for boiling water, heating up soup, or making rice. I would imagine a medium size sauce pan would be big enough for any of your cooking needs.
3. A stock pan is the next item I would recommend because if something is too big to cook in your sauce pan, just throw it in the stock pan. Plus it great for cooking a large amount of pasta sauce for a family dinner!
4. The final cookware item I consider a necessity is a baking sheet (maybe two). A baking sheet obviously can be used for making cookies (yum!), cooking up chicken nuggets, or even cooking a small pizza.
The not "so" necessities - but hey you might want these too:
1. A muffin tin is something I do not use, but if you are an avid baker, you probably would want to add one of these to your cookware stock.
2. A specialty cake pan may also be a necessity for your needs. If you like to bake a lot of different cakes (I am jealous of your talent), this is another item to add to your cookware list.
3. Now another item to consider is a griddle. A small one may come in handy if your kids love grilled cheese (or hey, if you love grilled cheese) but you can make that in a skillet as well.
So go ahead, throw out or donate those unused cookware items, because what person doesn't love more space and organization in the kitchen!?