I've always said that my second favorite period of historical miniatures is the "Age of Reason," particularly the Seven Years War. Although right now I have no photos of them, I have two reasonably sized 15mm armies from the SYW -- Frederick the Great's Prussians and Maria Theresa's Austrians. As they are the major combatants of the SYW (and the War of Austrian Succession that preceded it), so those were the first I painted. I have the miniatures for a Russian army, as well, but have painted up only a handful of figs.
Originally, when I purchased these troops, the rules set we were using was Warfare in the Age of Reason. We played it for a number of years, and it worked okay. However, since we did not do it on a regular basis, we were constantly refering to the rulebook to answer questions. And these rules are NOT well organized, despite the release of a second edition (which changes very little and is not a recommended purchase). So, playing Age of Reason became a frustrating experience, as we didn't remember all the rules and couldn't find them quickly when we looked for them.
Thus began my decade-long quest for a better set of Horse and Musket rules. Ideas came and went -- many inspired by articles I'd read in MWAN magazine. Nothing seemed to click, though, until we (my Sunday night gaming group) began to play Hordes of the Things fantasy miniatures rules. Hmmm, I thought. These ARE an excellently-balanced set of rules. Very much like our main miniatures set, De Bellis Antiquitatis (DBA), for Ancients. With only a couple tweaks, they'd work fine for the Age of Reason. And probably most importantly, we'd be playing a familiar set of rules, so wouldn't need to scramble when we did get around to playing the period, from time to time.
So, with a couple tweaks, I now use Hordes of the Things for my Horse and Musket era miniatures...and I labelled the newly revised rules, HOTT Lead.
Check out the Gallery section for pictures of my Seven Years War armies.