Guy Ritchie's King Arthur: Legend of the Sword, in theaters this weekend, is only the latest film to adapt the tales of King Arthur and his noble knights. There have been dozens, in several languages, beginning way back in 1904, with a silent film based on the Wagner opera Parsifal.It makes sense, right? The loose collection of legends in question represent an epic story filled with elements perennially ripe for big-screen treatment: the boy who discovers himself the rightful heir to the throne. The magic sword. The wise tutor. The battles that unite a kingdom. The noble knights, and their noble quests. And of course the love story, with its tragic ending.Filmmakers can approach such a sweeping tale from many different directions, playing up certain aspects, and dialing back others, to fit the story they want to tell. This narrative richness is one reason the legend of King Arthur keeps getting told and retold on the big screen.The other reason - equally important - is that the legend of King Arthur exists in the public domain.Below we'll take a look at some of the most notable cinematic interpretations of Camelot over the years.Before we do, though, let's stipulate that there are three essential elements to any film adaption of Arthurian legend - three boxes that must needs be checked, however obliquely, if the movie's gonna fulfill its promise.To wit:1. The Round TableI mean, duh. It's called visual iconography, look it up. Also the table represents something crucial about Arthur, the thing that makes him so enduringly appealing as a character, and as Britain's idealized monarch: he is flawed, yes, but he rules fairly. He sees himself not only as a uniter, but as a king among equals. The round table establishes his egalitarian bona fides. It's key.2. The Love TriangleFull disclosure: It bores me. I know, I know: it's called Arthurian Romance, after all. It's there to underscore Arthur's vulnerability, his flawed humanity, his emotional side. And in the right hands, it can serve to add layers of nuance to Guinevere, the story's only female presence of note who isn't an evil witch (Morgaine/Morgana/Nimue). I get why it's there. And I see why it's central. But it bores me.3. MerlinFull disclosure, part the second: Wheeeeee! Merlin! Magic and mystery! Pagan mysticism! Pointy hats! I love me some Merlin. He's there to connect Arthur to notions of eternity and fate and the unconscious, and without him, the legend of Arthur get diminished, its glamour fades, and it gets reduced to mere workmanlike alt-history. For me, the ideal Arthur-on-film fuel mixture is 20% Round Table, 5% Love Triangle, 75% Merlin. But I understand I am in the minority there. (Yes, I know: he's a late addition to the legend of Arthur. He was inserted by Geoffrey of Monmouth blah blah blah shut up. He's awesome. Merlin 4ever.)Let's take a look at nine notable onscreen Arthurs:Year: 2017Title: King Arthur: Legend of the SwordStory: Better than you think it's gonna be! Seriously! Charlie Hunnam's a jacked and genial Arthur, the dialogue is surprisingly nimble, and director Guy Ritchie keeps things moving at a brisk trot, bringing his distinctive visual style to the swords and sorcery genre. It's basically a heist film in shining armor. Lock, Stock and Two Smoking Baldrics.Several set-pieces involve Arthur learning to unlock the power of Excalibur, which feel like you're watching someone unleashing sick combos in Street Fighter.Sounds like a complaint. Isn't.Quibbles? Jude Law, as the eeeevil usurper-sorcerer Vortigern, doesn't go full-bore, Young-Pope-sinister, and you keep waiting for him to. Also, the CGI finale, which involves a a very silly-looking giant [redacted], is as big and loud and dumb as CGI finales tend to be.Running Time: And here's the other issue: 126 minutes. You chop half an hour off this thing, and you got yourself a tight little flick, perfect for watching from the couch on a lazy Sunday afternoon.Round Table? Yes, eventually.Love Triangle? No, weirdly. Hunnam didn't get a love interest in Pacific Rim, either. What gives?Merlin? Ssssssorta. Glimpsed at the beginning. But his traditional role is fulfilled by Ãstrid BergÃ¨s-Frisbey, as a sort of gothy (lower-case g!) mage given to marble-mouthed mystical muttering.The Completely Subjective Once and Future Final Score: 7 out of 10.Year: 2004Title: King ArthurStory: As "the real story behind the legend" treatments go, fairly effective, thanks largely to a cast that features every working U.K. actor. All seven of them. Directed by Antione Fuqua, this version turns Arthur (Clive Owen) into a Roman cavalry officer, Guinevere (Keira Knightley) into a badass Briton warrior, and Merlin (Stephen Dillane) into a tribal chieftain.Given its focus on battle scenes, tribal alliances, and soldiers venturing beyond a wall (Hadrian's, in this case) the film feels less Arthurian than G.R.R.Martinian.Running Time: 126 minutes (Director's Cut: 142 minutes) (Yikes.)Round Table? Nope.Love Triangle? Barely. More hinted at than shown.Merlin? He's there in name only, as the film thumbs its nose at magic, opting for a grubbier, more realistic take that makes its seem awfully impressed with itself.The Completely Subjective Once and Future Final Score: Where's the magic, man? Where's the showmanship? Where's the zazz? 5 out 10 - but an extra point for doing something novel with Guinevere: 6 out of 10.Year: 1995Title: First KnightStory: Another interpretation that downplays the magic and ups the shmoopy, wet-eyed romance. Stars Sean Connery as an aging Arthur, Julia Ormond as a winsome Guinevere, and Richard Gere as an equally winsome, floppy-haired Lancelot.Running Time: 134 minutes.Round Table? Prominently featured.Love Triangle? Hoo boy, yes. There's so much of it, it's more like a love pyramid.Merlin? Completely absent! Which might explain why the film feels so plaintively dull.The Completely Subjective Once and Future Final Score: 4 out of 10. Wait, no, minus one point for the lousy pun in the title. 3 out of 10!Year: 1984Title: Sword of the ValiantStory: King Arthur meets I Love the 80s. Lantern-jawed beef-slab Miles O'Keefe IS! ... Gawain! Sean Connery IS! ... The Green Knight! And this movie IS! ... Cheesy!But it's a good cheese. An aged cheese. A cheese with bits of, like, savory herbs and whatnot inside it. Consider: Connery spends the entire running time with his face covered in green glitter. It's like he got pranked after passing out in a Michael's.Worth seeing, if only for Peter Cushing, John Rhys-Davies and Trevor Howard (as an old, cranky King Arthur) looking sheepish.Running Time: Only 102 minutes! Which is, when it comes to the Arthurian film canon, positively nimble.Round Table? It's more a series of banquet tables? Imagine a medieval bar mitzvah.Love Triangle? Nope.Merlin? Well there's no shortage of magic, certainly, but no Merlin to speak of.The Completely Subjective Once and Future Final Score: It's not, strictly speaking, Arthurian, even though Howard plays Arthur. It's more a spin-off - an Arthurian AfterM*A*S*H. So: 5 out of 10 for the cheesy goodness, minus one point for its off-brand content.Year: 1981Title: ExcaliburStory: Oh, man. This is the stuff, right here. Arthurian legend as gleefully indulgent prog-rock concept album. John Boorman's direction is ... you know, not subtle: this is visceral, passionate and, given how often Orff and Wagner turn up on the soundtrack, literally operatic.Running Time: 140 minutes.Round Table? You bet, and it never looked better. Polished to perfection. The knights sitting around it look like shiny, tinfoil-encased birth-control pills convinced of their own nobility.Love Triangle? Geez, yes. Guinevere and Lancelot sport pretty much identical perms, so maybe that's the source of their passion.Merlin? No, not just Merlin. The most Merlin. Nicol Williamson is on fire here, sending his sinuous voice through an endless series of corkscrew turns and barrel-rolls. The film wisely picks up on a frequent theme of Arthurian legend - the fading of Magic and the rise of Man - and lets Merlin personify it, with the full force of Williamson's mercurial gifts. He leaves after the first act, and the film sags, but Helen Mirren as the devious Morgana picks up the slack. (This writer may or may not, as a kid, have worn his VHS copy thin rewinding the Merlin/Morgana seduction scene, so he could memorize The Charm of Making.)The Completely Subjective Once and Future Final Score: 10 out of 10. Yes, it's a little long, but that's unavoidable - just par for the Arthurian course.Year: 1975Title: Monty Python and the Holy Grail Story: An extended, disjointed, sketch-based riff on Arthurian legend. Every nerd of your acquaintance has at least five minutes of it committed to memory. It's how they recognize each other in the wild.Running Time: 92 minutes. Only one of many things this film gets right.Round Table? Nope. Camelot is glimpsed, but only in a throwaway gag.Love Triangle? Shyeah. Right. See above, in re: nerds.Merlin? Swapped out for Tim the Enchanter.The Completely Subjective Once and Future Final Score: 9 out of 10. Would have gotten a 10, but man, that ending still rankles, every time you see it.Year: 1967Title: CamelotStory: The Lerner and Lowe musical came to the big screen seven years after debuting on Broadway. The tunes are catchy, the cinematography's sumptuous, the film is leaden. Richard Harris talk-sings with the best of them, and if you ever need a pick-me-up, Google Vanessa Redgrave's take on "The Lusty Month of May" - homegirl positively chews those lyrics like they're salt water taffy. But it just keeps going on and on and on.Running Time: 179 minutes! The humanity!Round Table? Yup.Love Triangle? Very much so. Too damn much so.Merlin? Yes, but not enough. Not nearly enough. Just makes you miss him all the more.The Completely Subjective Once and Future Final Score: 7 out 10. Minus one point for not knowing when to quit: 6 out of 10.Year: 1963Title: The Sword in the StoneStory: Disney's animated adaptations of T.H. White's whimsical Arthurian bildungsroman is a charming, if slight, addition to the canon. Karl Swenson voices Merlin, and he absolutely nails it.Running Time: 79 minutes.Round Table? Nope, this comes before any of that.Love Triangle? Again, it's a prequel. There is some business with an amorous lady squirrel, but ... but that's probably not what you mean.Merlin? Yes, and he's in fine form, and there's lots and lots of him. Plenty of transformations and spell-casting - it's all any of us who always pick the Mage Guild in Skyrim want from a movie, really.The Completely Subjective Once and Future Final Score: 8 out of 10.Year: 1949Title: A Connecticut Yankee in King Arthur's CourtStory: A feather-light adaptation of Mark Twain's novel, starring Bing Crosby as a mechanic transported back to the court of King Arthur. Doesn't really tick off any of the classic Arthurian boxes, not that it's interested in doing so. But as an example of mid-career Der Bingle, perfectly passable.Running Time: 106 minutesRound Table? Not so much - this is another example of a golden-year King Arthur story.Love Triangle? None to speak of.Merlin? He's here, but he's not so much magical as evil - a charlatan scheming to usurp the throne. In a bad wig.The Completely Subjective Once and Future Final Score: 6 out of 10. Minus two points for that wig. 4 out of 10.