Easy - Battaglin Cromor - TSD bike.
Why? First really good bike, first Italian, first Columbus, red, etc....
I've owned it since 1996. Started life as 7sp, updraded to 8sp, 9sp, then coverted to a single speed. The only original parts are the frame and seatpost.
Went into hibernation for a while and then was reborn as a 8sp "hill bike" for the 2015 Dairyland Dare.
Haven't ridden it since I picked up the Superior, but I will.