Something I love about Nikons is that their modern DSLRs work to varying degrees with Nikon lenses that go waaaay back. Higher end Nikons (not the D3xxx and D5xxx series - don't get me started) work seamlessly with everything but the earliest manual focus lenses.
Not everyone wants a manual focus lens though.. and the good news is that in the 80s and 90s Nikon made some KILLER constant aperture lenses for the early auto focus Nikon film cameras.
Here's a great example, the Nikon 70-210 f4D. This constant f4 lens (maximum aperture doesn't change through the zoom range) has recently been replaced with a new f4 VR lens that is of course better, but costs $1,500!
Is this lens good? Yes - it's great, and it's kicking around for under $200 on eBay, and as low as $100 if you're lucky (which I was).
I love my twin ring Nikon 80-200 f2.8 but I gotta tell you, there are definitely times I don't want to lug it around, and this cheap little f4 performs well enough that I'm not going to kick myself if that's all I've got with me. If I'm travelling, then this is going along for the ride (with the 85mm f1.8G, 50mm f1.8G and vintage 20mm f4.
Here's a size comparison with the f2.8D and a very nice beer.
.. and hey - there's no point talking about a lens and not posting some photos taken with it. Here's a sample taken in evening light near home that illustrating sharpness, available depth of field control and general handling. All shot on Nikon D3s.