Ah well, I do love ALL of The Matrix fights, but my absolute favorite is the very first Neo Vs Smith fight. The Burly Brawl and Super Burly Brawl are pretty awesome, but they could have been so much more. The first fight is simply flawless. A classic duel with a futuristic update.
My runner up is actually the Teahouse fight. Short and simple by comparison, but perfect in its execution.