British military history!
Well, Rorke's Drift was dramatic and goes down in history as an inspiring example of cussedness and glorious defiance, evoking emotions rather like the Alamo does, but not much really for tactics and strategy.
BUT for my own view, this amateur historian votes for the 1st Anglo-Sikh War, and specifically for the three main battles around the Sutlej River. Vastly outnumbered, outgunned, out everything, and they used tactics and maneuvers to gain the upper hand. Three battles, and three days of total absolute military genius. Had they dug in like at Rorke's Drift, it would have been over in a few hours. Quite astonishing to read the diary accounts of the veterans.
During the peace negotiations, Queen Victoria was gifted the Koh-i-Noor Mountain of Light diamond. Arguably the largest diamond of its kind in the world. She wore it for a while in her crown, but ultimately decided it looked too gaudy - it is obscenely big. Today this diamond is in the Tower of London.
If you're visiting the Tower of London, it's one thing you'll not want to miss...
I saw the wiki has an article
http://en.wikipedia.org/wiki/First_Anglo-Sikh_War