I personally love the look. Gray gives you the same "stand out effect" that black does, but it does it in the chicest way possible. It's easier to wear and apply (think of all the times you've had to take a q-tip to your freshly painted black nails to fix mistakes).
Lighter grays are great for summer and also work well for the transition into fall. The color is unexpected and unique, which is exactly what you want in a polish.
My fave? Sally Hansen's Complete Salon Manicure in Commander in Chic. The hue has just the slightest bit of purple to it and is anything but boring.
You can pick up a bottle for under $7.