I am a huge fan of Nelson and Trafalgar. I have been on the HMS Victory and own a piece of the decking removed when it was refitted in 1922. It is entirely possible based on her history that this piece of decking was at Trafalgar. That said it was not the battle that made Britain Great. Months prior to Trafalgar Napoleon had begun moving troops from the coast effectively ending any chance of an invasion. Of course the Brits did not know this at the time of Trafalgar. From a Naval perspective I would think there were a number of sea battles that were more important then Trafalgar. The First of June 1794 and the Battle of the Nile (from which the French never seemed to recover) come to mind. Something for the Brits to contemplate while they freeze their asses off this winter.
I have a repro Land Pattern Brown Bess. A few years back I was shopping for flints and came across an antique firearms dealer that was selling a set of Napoleonic era knapped flints. Apparently, at one point, in fear of a potential invasion by the French, the British armaments industry went into overdrive prepping flints, ball and powder for defense of the home isle. When that never came about, the excess were sent to the colonial possessions just in time for the conversion to percussion caps.
I bought a couple sets of the flints (with provenance.) It's fascinating to fondle them and know that they were furiously shaped by some arsenal worker in Leeds or Manchester over 200 years ago doing his part to face down what he had to believe was an existential threat...