Jeff,
I'm just using the kit lens which is a Nikkor 18 - 55mm. But what I really want is a good macro lens.
Macro's are the meat of my photography! My 105mm F/2.8D Nikkor is my favorite lens. Shooting with a macro turns any place on any day an excellent shooting day. You can purchase these older D lenses for around $300 and it's at least as good as the newer G lens and many purport it to be a better lens. It certainly is smaller and weighs considerably less, not to mention it's made of metal and not plastic.