The Italian Job (1969)
No, not that Marky Mark piece of crap. This is the bloody original, innit? Not only is this Michael Caine-starring heist flick a full-on comedy (and a great one, at that), it ends with…a literal cliffhanger. The gang of thieves on one side, their loot on the other, in a bus balanced precariously over the side of a mountain. "Hang on a minute, lads. I got a great idea." The end. Brilliant.