Here is my ranking:

1. RoTJ - Vader vs. Luke. Not much to say here, it just is perfect.
2. ESB - another lovely father and son experience with the big reveal at the end. I don't think it is as grand, but what is compared to the OTs finale?
3. TFA - I just loved Kylo Ren struggeling with his injury while still being a real menace and Rey discovering great powers within herself.
4. TPM - The finale was the only thing amazing about that movie. It did not yet venture into the overstylisation of the later prequels, yet and had one of the best pieces of Star Wars music.
5. ANH - Obi Wan and Vader. Well, from a story telling standpoint this should be higher. This duel has a lot of meaning, great characters and good dialogue. When it comes down to the actual fighting, though, it is janky as hell. Some of the least realistic swordfighting ever brought to cinema (really, they aim for each others lightsabers!). Its significance makes me look past that in the movie, but it is a flaw.
6. RoTS Obi Wan vs. Anakin - its too long, but I do like the set, the motivations (if only they were portrayed better) and parts of the choreography. I would rate it 'meh'.
7. Any fight involving pinball Yoda. I really want to forget that happened, okay?

Savage and Maul vs Sidious is one of my favourites. I'm sure the upcoming Ahsoka vs Vader will be a well.

Does Kas'im vs Darth Bane count?

Does Kas'im vs Darth Bane count?

No, because I am the absolute ruler of everything and that is against the holy rules that I have decreed!

Ofc it counts when you like it!

Yoda vs Sidious in The Clone Wars season 6 was good as well.

There's a bunch of good fights in the series, some better than the movies.

Dooku's fights were good as well, all about measured control.

Revan vs Bastila?

Failing that,

Yoda vs Sidious in The Clone Wars season 6 was good as well.

The vision sequence one ?

That's the one.

Thinking about this, I keep coming back to the fight between (spoilered for people who haven't seen season 2 of Rebels yet)

So, yeah, that. Loads from The Clone Wars as well. From the movies? I actually like the Anakin/Obi-Wan climax in Revenge of the Sith, but I prefer the two of them against Dooku, both times.

That's the one.

That one is cool but since it wasn't "real" I had kind of forgotten about it.

Rotj

Esb

Hope

The prequel fights are all pretty soulless dance numbers with no emotional gravitas.

ESB is perfect, simply for the sheer emotion and physicality to it, RotJ is close for same reason. Duel of the Fates hits the balance between flashy and physical, the rest of the prequel fights miss the mark quite dramatically there. On to the animated stuff, Maul vs Vizla is stunning, as is Ezra and Kanan vs The Inquisitor at the end of series 1 of Rebels, and Ashoka vs the Inquisitors in series 2.

But the best, by far, is Rey and Finn vs Ren in TFA. Absolutely brutal and physical, so emotionally charged, looks stunning and sounds perfect.

Yoda vs Dooku. Yoda hobbles in with hs walking stick and leaves the same way. In between he's like Ricochet Rabbit.

1) Empire: The first time you get some real emotion behind the lightsabre fights. Just before Luke loses his hand you can see Vader giving in to his rage.

2) Jedi: Culmination of all the tension between Luke and Vader is just an awesome spectacle!

3) Beginning of the Obi / Ani fight in Sith: I agree with most people that the fight was too drawn out, but the starting minutes of it were fantastic. The hatred and sorrow are the most emotional parts of the prequel trilogy.

While we're on the subject, there is actually a way to make the ESB and RotJ duels even more epic. The highlight of the prequel fights has to be their backing music, and thanks to the magic of having two Youtube tabs open at once, it's possible to add the epic new music over the classic fights and add a whole other layer to them. Open up Luke vs Vader in RotJ and start playing Duel of the Fates at the same time, prepare for 5 minutes of simply amazing viewing. Battle of the Heroes works well enough with the ESB fight, as it has hints of Vader's theme in, and matches the pacing quite well too.

ESB is perfect, simply for the sheer emotion and physicality to it...

...and the way it's a total shift from traditional notions of heroic combat.

Luke's warned he's not ready to face Vader, that he needs to finish his training before he leaves Dagobah. Normally, you'd think a hero would find a way to overcome the odds, save his friends and win the day through courage or resourcefulness.

To start with, he looks like he could actually do it. But then Vader brings the Force into play, the tone shifts, and it becomes clear that Luke's hopelessly outmatched.

And he loses. And he doesn't just lose, he loses his hand as well. And then the big revelation, followed by Luke just barely escaping with his life.

It was a watershed moment.

Rotj Luke/Vader or TFA Rey/Kylo

Savage and Maul vs Sidious is one of my favourites. I'm sure the upcoming Ahsoka vs Vader will be a well.

1. RotJ

2. TPM

3. RotS

4. ESB

5. AotC

6. TFA

7. ANH

Duel of the fates is my favorite. With anakin vs obiwan a close second.

My only complaint is that the colors should be swapped.

1. RotJ

2. AotC, Yoda vs. Dooku

3. TPM

4. ESB

5. RotS, Mace Windu vs. Palpatine

Actually, I love them all.

Ryan vs Dorkman

and

Ryan vs Dorkman 2.

Look them up on youtube, they're awesome.

For me it had to be the Phantom Menace with Obi wan + Qui gon vs Darth Maul... well set piece with the best music in all of star wars, Duel of the Fates...

Ok that's enough. Empire Strikes Back Vader v Luke is one of my favorites as well.