I could not live without my Dutch Oven. I use it for browning meat and vegetables. I use it for frying things, since the tall sides reduce the amount of splatter in the kitchen. It is good for making stews and chili.
Lodge makes some of the best cast iron pans, and I really like the pre-preseasoned ones. The pre-seasoning reduces the amount of work you need to do before its initial use, but I also really like it because the pans have a dark (almost black) uniform color from the start. You need to use an unseasoned pan dozens (or hundreds) of times before it works and look perfect.
My Dutch Oven has a wire coil handle which reduces the need for hot plate holders. It is 10 ¼ across and 4 inches deep. I bought mine from Amazon; got a decent price and free shipping. Lodge Cast Iron has a lifetime warranty.