Okay, this isn't speculative fiction per se (although it borders on fantasy) but I hold this movie up as a terrific example of good characterizations and clever plotting.
The heros are a well-rounded team of hand picked experts. This is just like every other heist film, but still, it's entertaining to watch them work as a team. Their chummy relationship felt a little contrived in places, but I overlooked that. Any story with interesting characters working and complementing each other pulls me in. The minor characters are interesting too.
The plot was the best I have seen in a while. They rip off a ton of gold bars in Italy, using a method I have never seen before. Unfortunately, one of their team betrays them and takes it (you know this already from the previews).
When they find the guy they hatch another clever scheme to get it back, but -- here's the kicker -- it doesn't work (you can feel this one coming since the movie is only half over at this point). So they have to do a quick rethink, and come up with yet another clever scheme. And there is another after that.
For most movies, the plot well runs dry after one twist or two. This one keeps them coming.
The acting was good, but the screenwriter deserves the credit for this movie's success.