X-Wing Alliance: the bit (don't know which mission at the moment) where you emerge from hyperspace in the Otana facing a veritable massive fleet of Star Destroyers, much like the Rebel Fleet at the end of Return of the Jedi. Only this time it's just you. Alone. Run Away.
X-Wing: Destroy the Intrepid. In the original X-Wing it wasn't possible to target small components like laser cannon on large ships, meaning that other than the Star Destroyer's shield generator towers (which you had to manually aim at) you couldn't weaken capital ships by taking out their guns when engaging them at close range first. Taking down Star Destroyer Intrepid in the original X-wing actually felt like a real accomplishment compared to how easily they went down in subsequent games in the series.