Since getting into multisport in 2004:
2004 - 2009: Hybrid - Mikado Yorkdale. Exclusive ride in 2004, relegated to commuter in 2005, in the shed since 2009.
2005 - 2014: Road Bike - KHS Flite 320. Exclusive ride from 2005 to 2007, occasional use 2007 - 2010. Relegated to trainer 2010 / Son uses it occasionally
2007 - 2015: Tri Bike - Cervelo P2K. 80% of all rides from 2007 to 2011; multisport competition from 2012 to 2014. Sold (reluctantly) in 2016.
2011 - present: Road Bike - Cervelo R3. 90% of all rides form 2012 to present. Upgraded gruppo and wheels in 2017.
2012 - present: Cross Bike - Jamis Supernova. Spring bike, gravel bike, back-road-baller bike, occasional Cyclocross race. Probably < 500 Km per year, still fun to ride.
2015 - present: Tri Bike - Cervelo P2. Weekly club duathlon, plus tri competition. Will use 1-2 times per week when training for ironman. Occasional Strava hunting.
13 years, 6 bikes total, currently still own 5, only 4 are in regular rotation. I feel inadequate for this thread.
But for posterity..
First "real" bike, 1979, Raleigh Grifter. Sweet baby 3-speed BMX style. You could bend the back fender to rub on the tire and make it sound like a motorbike.
First "real" road bike, 1986, Raleigh Record. Candy red, with full internal cabling.