In an early book, Jacen finds himself captured by the Vong. He's trying to call his lightsaber to him, but he can't seem to do it. Then it flies away from him. He hears it ignite...and then another lightsaber igniting. His Uncle Luke has arrived, and while Luke doesn't start a fight with the Vong, he kicks nine kinds of hell out of them when they don't stand down. Primarily by use of a Force tornado that pummels them with rocks and debris from the ground around them.
Ganner Rhysode's Last Stand in Traitor. He literally becomes one with the Force while holding off hundreds of Yuuzhan Vong warriors single-handedly, finally pulling a Samson and collapsing the building on himself and everything in the vicinity before he's overcome. This impresses the Vong so much that he winds up as a central figure in the Vong's Jeedai heresy, an invincible warrior called the Ganner who guards the gateway to the underworld.
"I am Ganner. This threshold is mine. I claim it for my own. Bring on your thousands, one at a time or all in a rush. I don't give a damn. None shall pass."
In one of the later books Corran, Anakin, and Tahiri are on a space station orbiting the homeworld of the Givin, whose leaders were not particularly happy to have them there. The Vong show up, and Corran assumes the Givin will turn them over to the Vong. The Givin, however, begin pitched battle with the Vong. Confused, Corran asks the Givin leader why the Vong didn't transmit their usual "Surrender the Jedi and we'll let you live" message. The Givin leader's reply? "They did. We did not believe them." After seeing dozens of worlds throw Jedi to the wolves (and get destroyed regardless), it was both awesome and refreshing to see one planet with a healthy dose of Genre Savvy.
Jacen's Final Battle with Onimi in "The Unifying Force", wherein Jacen achieves oneness and activates Force Light in order to turn Onimi's own poisons against him, melting him into a puddle of goop. Considering all of the atrocities that Onimi has caused purely to ascend to Godhood, it's more than righteous and it causes the destruction of the Vong Citadel, ensuring that the War will finally end.