Plenty of contribution already,so I'll just add a personal anecdote. Some years ago I happened to have some beers with a Latvian Russian,who lived here, in London. He tells us that he doesn't get the Brits. He just doesn't understand the reasoning in some situations. I ask to elaborate. He says: last year, I had a pretty serious trauma and ended up in a hospital. It's so bad, pain, lots of tests,etc. And I'm pretty fed up with all of it. Then, one day, a surgeon comes in, says hello and asks me 'how are you?'. And I reply: 'really bad!'. And suddenly surgeon's face changes: his eyes start moving faster,he looks at me and then observes the room,then at me again. Then the surgeon,in a slightly panicky voice ask me again: well what's wrong,is it the food? Is it the nurses? Did they do all the tests? What's going on?' Then the Russian looks at the doctor and says: well look, I'm in a hospital, I'm ill as hell, I'm in pain and you have the audacity to ask how am I? Are you crazy? It should be pretty clear that it's definitely not my day! The surgeon goes on to explain the subtleties of the question and etc. At that point I already lived in the UK long enough to understand the doctor's position but I also found the Russians point to be absolutely hilarious.
From personal experience I find the Russians absolutely hilarious even without much smiling (the young ones smile more).They are somehow similar to Italians,who are also hilarious, but as is the case with the Russians, the funniest things tend to be equally tragic too. Kind of a never ending tragicomedy on full blast.