Not to repeat any movies that has already been mentioned, but a lot have been good.
One specifically that I would recomend would be the original Excaliber (1981) directed by John Boorman.
Cast of Patrick Stewart as Leondegrance and Liam Nelson as Gawain.
This was by far the most realistic excaliber I have ever seen. They say the battle scense used the real sounds of fighting instead of dubbed in special effects.
Just my opinion.
