My favorite tool(s) at our shop has to be the lathes. After making 20+ of those Delrin pullies for our new drivetrain, who wouldn't get attached?
Ahh...the smell of formaldehyde in the evening!
(Delrin is a plastic produced by the polymerization of formaldehyde, and when you cut it, all of the lovely smell gets wafted toward your nose, And oooh boy does it smell!)
Here are the pullies