The Super Battle Droids get one in the battle with the Gungans on Naboo's hunt mode. They have grenades and fusion cutters, the droids have automatic rifles, shotguns and wrist blasters.
There's normally one per campaign mission. In the tutorial alone, you raze dozens of capture points, take out endless waves of enemies and even take down an entire column of Spider-Walkers, single handedly.
Sometimes, you may be the only soldier left on your team, while the enemy has about 30 or so. If that happens, and you manage to stay alive, you can single handedly decimate the remaining enemies with just your cunning, your guile, and the weapons you carry. As Long as There Is One Man, they. Will. Not. Win.
Republic ending in Galactic Conquest mode in II, which is also a Crowning Moment of Heartwarming, with Mace Windu killing Palpatine, Obi-Wan killing Grievous, and Anakin becoming a Jedi Master.