The movie, about the extraordinary civilian rescue of soldiers stranded at Dunkirk in 1940, currently has a 98% critics' rating on Rotten Tomatoes and a 97% score on Metacritic.
Here's a roundup of some of the more glowing reviews:
Todd McCarthy, The Hollywood Reporter:"'Dunkirk' is an impressionist masterpiece... this is the film that Christopher Nolan earned the right to make thanks to his abundant contributions to Warner Bros. with his 'Dark Knight' trilogy. He's made the most of it."
Richard Roeper, Chicago Sun-Times: "Nolan has crafted a tight, gripping, deeply involving and unforgettable film that ranks about the best war movies of the decade."
Bilge Eberi, The Village Voice: "The nerve-racking war thriller 'Dunkirk' is the movie Christopher Nolan's entire career has been building up to, in ways that even he may not have realized."
Alonso Duralde, The Wrap: "Nolan quite cannily weds a studio sensibility (relentless action! staggering visual effects!) with the kind of subtlety and dramatic implication we rarely see in a film that doesn't involve subtitles."
Rosie Fletcher, Digital Spy: "'Dunkirk' is the film Nolan has been building to his entire career. It's his masterpiece, it's the best film of the year so far, and it's the one to beat come awards time."
Christopher Machell, CineVue: "'Dunkirk', tellingly, is the first of Nolan's films to induce tears in its final frames. The director's technical mastery finally transcends craft to become art and, as a result, this is his best film to date."
Joanna Langfield, The Movie Minute: "Christopher Nolan's epic isn't just the best film of his career, but one of the best war movies in decades."
The one negative review (so far) on Rotten Tomatoes is from Harvey S. Karten of Compuserve, who gave it a "C" rating and writes: "The story of a miracle should have been thrilling; but given the non-linear approach, 'Dunkirk' lacks the kind of center that would prompt the audience to stand up and cheer."