To be honest, I have never really had a piece of equipment "inspire" my creativity. It is really a matter of having a piece of equipment that supports the vision I create in my mind. This said, I do love the Nikon Creative Lighting System with its compact nature and ease of use to create down and dirty lighting.
For me, it is solving lighting problems when photographing law enforcement officers at night in complex scenarios involving multiple subjects/groups, moving vehicles, charging K9 dogs, hovering helicopters, ... using my herd of twelve SB800s. Once I reached the limitations of Nikon's IR CLS technology, I acquired a herd+one of RF Pocket Wizards (six Plus II, and seven MultiMax units) and continued on my merry way in full manual mode. No big change for me, as I was in manual SU-4 mode with the herd most of the time anyway, because I often needed to illuminate more than three groups of subjects. The greatest advantage of the PW approach is greater range, and I can hide remote units behind subjects and other set components and not worry about line of sight alignment.
In my personal view, illumination is the sine qua non of photography.
HBB in Phoenix, Arizona Nikonian Team Member
Photography is a journey with no conceivable destination.
The only creativity that any equipment inspires in me is with regard to the justifications I must create to tell my wife why I need to buy another piece of gear.
As to what equipment best supports any visual creativity I may have, then hands-down my answer would be a tripod, as it helps me to better visualize a subject regardless of the lens or camera mounted to it.
I am inspired mostly by equipment that works very well. Originally it was the F100. Now it is generally a full-bodied Nikon.
More correctly it is whatever equipment fits my current feeling. Sometimes a long lens for sports/action. Maybe a 50mm prime or the 24mm f/1.4 for simplicity. The macro lenses can be very fun in the house with a good stereo, a beverage, and no need to go anywhere.