the list is long and so vast from very small units to great large one that move dam gates. so you need to tell us in what context you are interested in for a good answer. as well as D.C.. A.C. and some rather interesting ones.
For a start - what sort of jobs do you want those motors to do? There are very small motors in small hobby drills, and much larger motors to start your car or power an elevator.
Don't you have a private room somewehere that you can use?
That depends on what you need or want from the motor.
Running a drill press isn't quite exactly the same as running an air compressor.
On an electric motor test-rig, built to suit the range of motor sizes and power outputs you wish to test.
You need to elaborate on the electric motor type and use, AC,DC, Induction, 3 phase reversible etc.
I suppose that depends on what you want to compare them FOR.
What kind of electric motors?
You need to disclose some information if you want an answer.
the story is long ... i shorten it....
in general motors are two types ....AC and DC
AC types.... single phase and three phase
synchronous and asynchronous
motor parameters ...
rotations per minute
what are your desired motor parameters?
what do you want to use it for?