Column, Line and Square was the first set of Napoleonics rules that I ever played — and I suspect, the first set that many people played. We called it Column, Line and Slaughter, though, becuase slaughter was the usual result.
Still, it was fun to play –especially with 25mm figures.
Sadly, the set is apparently no longer in print. But you can get the rules here, free for the downloading.
Natholeon’s Empires offers a set of free wargames rules for the Napoleonic Wars.
Paul Leniston offers a set of free wargames rules for Napoleonics. He and his gamer wife have been playing and testing them for many years.
Into Glory Ride is a set of free wargames rules for battles set in the Renaissance and beyond. It covers the era 1500 – 1900.
Jon Linney offers a set of Fast Play Napoleonic Rules. The author writes:
These rules provide a fast paced game with simple rule mechanisms that allow players to concentrate on their tactics and enjoy the ‘look’ of their tabletop battle, rather than have their heads buried in rule tables. Elements shoot and fight individually but move and test morale within their unit. One or two rule mechanisms have been ‘adapted’ from other rule systems (as I liked them); as they say imitation is the sincerest form of flattery! Players will need a table approximately 6′ by 4′ laid-out with suitable terrain. At least one D6 die and a measuring device each (measuring stick or rule), and of course two opposing armies. The measurements are for 15mm figures.