If you are interested in cooking, or if you know someone who is interested in cooking and is in the process of building up their kitchen, and there's a budget to consider, there's a great article on that here. I agree with all of it, I think.
Things that have been particularly helpful to me over the years:
Big cutting board with handle
Big mixing bowl with cover
A good wok
(these are in addition to the usual things - spatulas, frying pans, copper-bottomed pots if you're fancy, etc.)
I have an immersion blender that I really like, but honestly, I mostly use it for soups. It could be used for more things, and that helps to justify its purchase (also the fact that I think it was $20) but most people already have regular blenders and those are fine for soups too (though potentially messy).
I've also got several teapots. These aren't strictly necessary (there are so many ways to make tea), but having *one* teapot can be very helpful if you have people over and more than one person wants tea.
If you're into cooking but you don't have cable, PBS has a lot of really great cooking shows. My very favorite is "Jacques and Julia: Cooking at Home." If you don't already love Julia Child, you will. It's also incredibly informative.