Caught this classic at the Girls' School Cinema in East Perth recently and I'd forgotten how good it was. It's a touch under 3 hours but even sitting on a weird beanbag thing, trying to make the most of the bottomless popcorn (I don't even really like popcorn but it was part of the prize), didn't detract from the fun of Sergio Leone's madness. Like most spaghetti westerns, this was filmed with the actors speaking their own languages - Spanish, Italian and English - with voice actors dubbing over in post. Apparently, even the three leads had to do their own dubbing as the whole film was shot without sound.
Speaking of the leads, the film starts in reverse - Eli Wallach, as Tuco, is introduced first, then Lee Van Cleef, as Sentenza (or Angel Eyes), and finally Clint Eastwood, as Blondie (or The Man With No Name); so The Ugly, the Bad and the Good. Van Cleef gives good nasty and Eastwood is laconically funny but Wallach is the star for my money. He has all the best lines and gets a few meaty emotional scenes (see his meeting with his padre brother) that the other guys don't really have. His double act with Eastwood's unruffled straight man is the highlight of a film littered with them.
There are loads of iconic set pieces - Tuco saved from the noose by Blondie in a recurring scam; Tuco and his gang trying to creep up on Blondie while an army marches noisily through town, until it stops; Blondie's desert march; meeting Sentenza in the prison camp; the bridge sequence; and the final Mexican stand-off in the cemetery. The story is constructed with crosses and double crosses and it flows superbly. Much of this is down to Ennio Morricone's legendary score and Leone's penchant for close-ups, though the amoral tone of the film is a big plus too. And I didn't expect to be laughing so much - it might be the funniest western I've seen.
Though I don't think it's essential to see these prior to TGTBATU, but why not Leone's two preceding 'dollars' films - A Fistful of Dollars (1964) and For a Few Dollars More (1965). Both star Eastwood, Van Cleef joined the second one. Even better is the original of Fistful, Akira Kurosawa's Yojimbo (1961).