In no particular order...
Rapid Fire: I'd have to choose the scene where he's in the bad guy's den, the cops are outside but are pinned down by gunfire, and Brandon has to take down almost the entire room. Great.
The League of Extraordinary Gentlemen: the scene in Dorian Gray's study/library, where the Fantom's gunsels have the League trapped, until a disguised Tom Sawyer creates an opening. Then you have Captain Nemo kicking serious ass, Sawyer and Allan Quartermain shooting several bad guys, the Invisible Man bitchslapping a guy using a big book, and Dorian Gray taking a full clip of bullets at close range, then taking the guy out. "What are you? I'm complicated." Then a straggler grabs Mina Harker at knifepoint, right before she turns on him and bites his throat out. Awesome.
Steven Segal in Hard to Kill. The guy can't act his way out of a paytoilet but he gives great fight scene.
Most of the lightsaber battles from the Star Wars prequels. Yeah, the movies weren't great but still... Darth Maul vs. Qui-Gon and Obi-wan. Obi-Wan & Anakin v. Count Dooku v. Yoda. Yoda vs. Palpatine/Sidious. Anakin vs. Obi-Wan. Fantastic.