There have been many accounts of the Arthurian saga over the 1500 years, the best thought of the past century has been T.H. White's "The Once and Future King". Though White's prose is good and engaging, the narrative arc through is tetralogy-in-one edition is problematic enough that it sometimes overshadows the wonderful characters he has developed.
The first of the four individual works, "The Sword in the Stone", is the best of all four. White's writes wonderful characters, especially young Arthur (aka Wart), in well-rounded depth. The narrative flow of this work is the best of any of them and sets up the reign of Arthur that makes the reader look forward to seeing what happens next. Unfortunately in "The Queen of Air and Darkness" the characters are not well rounded and the narrative aimlessly wanders between England and the Orkneys without connecting the two until the last chapter when an evil scheme comes to fruition that the reader did not know what actually happening. The third and longest of the individual works, "The Ill-Made Knight" focuses on an ugly Lancelot, his love affair with Guinevere, and the knightly exploits of the Round Table. While this individual work is somewhat engaging, White emasculates Arthur both physically and mentally that continues into final individual work, "The Candle in the Wind", while other characters aren't even given much depth or story arc.
Throughout the entire writing, White injects himself and modern day elements throughout the entire book making it hard for the reader to keep to the narrative flow and maintain a "suspension of disbelief". Another unfortunate decision by White was to insist his story was real history of a part of the medieval era then mention "the supposed Henry III" or "the supposed Richard the Lionhearted" throughout. Also White assumed that his readers were versed in Thomas Malory's "The Death of Arthur", which I must admit a half century ago might have been the case, nowadays readers ironically look to "The Once and Future King." And there were White's tangents, whether it was philosophy or history, that were beautifully written but had no bearing whatsoever on the plot or characters or anything else he had just written about before he went down those literary side roads.
Upon completing "The Once and Future King", I can see why many people enjoyed it and rated it highly. However, I personally can't ignore narrative stumbles or downright tangents that made three-quarters of the book harder to read than the section covering "The Sword in the Stone". My advice before reading T.H. White is to read Malory's book first and be prepared for references from the 1930s to the late 50s, or you'll be taken aback.