If you could own only one item of Star Trek technology, what would it be? We're not talking about patent rights, just having a single item in your possession.
Hand phaser for those pesky traffic jams?
Transporter to go anywhere you want in 15 seconds?
Replicator because you hate to cook or go shopping?
Fully armed shuttlecraft in the garage?
I'd probably go for a holodeck, since I'm on the computer all day anyway.
Don't limit yourself to these.