Better USB cables emboss the logo so that one can tell which end is the top even in the dark.
But the absolute best is Logitech's solution: http://www.ebay.com/itm/Original-Logitech-Micro-USB-Cable-/2...
Logitech's solution ensures that you always effortlessly plug your cable in correctly on the first try. No need for reversible connectors like lightning, just use a well designed cable.
EDIT:
it appears most people aren't seeing the innovation. Check out the last picture in the linked set. There's a very large bump on the micro USB end of the cable that ensures that it's pretty much impossible to pick up the cable with the top end down.