We want to communicate the following values to our customers: trust, seriousness, agility, reactivity. The logo should also look nice on different supports like cars or clothes. We want something sober, distinctive, elegant and simple but original. It should say "You can trust this company. It will be your partners for years".
Basically the logo should have very few colours, the company's name should be easily readable but playing with it is possible.
The graphical element, if any, should be stylised, very light and should convey an idea related to the company's name or business area. This graphical element could also represent a wild animal like a tiger/cougar/cheetah for example, to symbolize the agility of the company. A connection between the graphical element and the company would be appreciated. It could be position, colour or effect.
For us, a good logo is memorable, very simple, aesthetic, timeless. On the opposite, complex, heavy, fashion, funny are not interesting.
This page on pinterest has a few logos which we like. http://www.pinterest.com/sp1404/logo/