Here's something for that 40-something Lego nerd in your life. A Lego Commodore Amiga, complete with internal circuit boards so you can carry out your own rudimentary repair work when something goes wrong.
It's only at the submissions stage on the Lego Ideas portal, and is probably a bit niche to ever make it into construction, but still. If you nick enough bits from your kids' endless fire engine and Star Wars sets, it might be possible to knock up a DIY model yourself. [Lego Ideas]