Apple Cinema Display 27″ Widescreen LED LCD Monitor. I paid £580 off eBay in August and a ridiculous amount in postage. It’s one of the earlier ones so no Thunderbolt out, just 3 USB.
Dell XPS 8700, 32G, 3TB+256G SSD, AMD Radeon HD R9 270 2GB GDDR5, 3.9GHz i7-4770. I can put a clean Ubuntu 14.10 on it if you want. This thing is a BEAST of a desktop! Paid £900.
These are great but back to the MacBook Air for me!