Jedi Knight series.
The lightsaber combat was so much fun.

Here we go... My first fediverse comment, and it's to say that to this day I think "Tie Fighter" is my all-time favorite video game.

Star Wars The Old Republic. Basically KOTOR with mmo elements. You could play it as a single player game if you wanted, with a lot of story content.
But doing flash points and PvP with my friends was fun too. Buying strongholds and flagships then decorating them was fun as well.

I want to say X-Wing vs Tie-Fighter, but if I'm being honest it was probably Dark Forces.

How can you have just one? How can you compare them?

Tie Fighter, XvT and X-Wing Alliance are some of the greatest space sims to ever grace a computer.
Dark Forces brought FPS to Star Wars! Jedi Outcast was a transcendent experience when it came out - the dismemberment! The lightsaber trails!
KOTOR is an absolutely classic Star Wars story in the same style as the OT, and KOTOR2 is a fantastic deconstruction of classic Star Wars, both with well written and memorable characters.
OG Battlefront and Battlefront 2 brought us some awesome squad shooter goodness!
Jedi Outcast and Survivor giving us some awesome modern Star Wars.

Rogue Squadron, Empire At War, Republic Commando, Episode 1 Racer, even the two MMOs Star Wars Galaxies and SWTOR, all solid games. There's no way I could pick just one.

Jedi Knight 2, the multiplayer lightsaber duels were one of the best gaming experiences I ever had.

Original Knights of the Old Republic easily takes the first place for me. Fallen Order and Academy comes 2nd and 3rd.

Ahh what I wouldn't give for another Obsidian SW RPG.

I absolutely loved Empire at War

Super Star Wars, Return of the Jedi on Game Boy. Not because it's a good game, far from it. It's because I'm old and have memories of trying to play this. With dying batteries and at an awkward angles so I could get light on the screen. I just accidentally found out it had this awesome Super Game Boy border too.