One item on my lust list is a Hermes clic-clic. Timeless, elegant and striking. I think the sapphire blue against the gold is stunning. (Also in alignment with my love for consignment stores and used goods, this is available on The Real Real, along with many other colors.)
I think in terms of classic pieces of jewelry that will never go out of style, this might be on my list of top 5. Others on the list include a Harry Winston Watch, David Yurman cable bracelet, and a Cartier Ring.
What is on your list of dream jewelry?