Must have:

1. comfortable - provide riding in upright position; stack : reach ratio greater than or equal to 1.50

2. Drivetrain with wide range of gears suitable for hills in the city;  the lowest gear inches at least 20. Range preferably from 18  to 110 gear inches. 

3. Tires wide enough ( at least 40 mm) to absorb many bumps on Toronto roads and gravel - off road rides outside the city

4. Long wheel-base to allow for panniers and stable ride

5. Ability to mount mud guards

Nice to have:

1. Relatively light frame 

2. Disc brakes (not hydraulic) 

So far, I have twice accomplished all under "must have". "Nice to have" remains an elusive dream.

What is your perfect bicycle?