I have created a Pinterest board with some examples of good logo design that are simple, distinctive, versatile, appropriate and timeless.
Some examples of good logos are here: https://www.pinterest.nz/ellagl/branding-and-visual-identity/good-logos-week-3/
I must say, I found it really hard to identify if the really contemporary modern logos that I love are timeless? Because Pinterest makes trends so affluent so fast, I can not tell if they are good logos for the market at the moment, or will they stand the test of time.
Also, what I did notice is that the more simple the design, the more effective and timeless it can be.