Salyut-7. It's unashamedly campy at times, but the spacewalk scenes are better than those in Gravity, the spaceship interiors are fantastic, its based on a true story, and its got a class and style of its own. Big plus that its not a hollywood action flick. If you haven't seen it you really should!

The director also recently flew to the ISS and shot a lot of footage for his next movie, can't wait to see that.