Hi Birma,
Well, the funny thing is I actually live in one of the the most densely populated area in the North-Western Europe (Randstad area in the Netherlands) with around 5500 residents per square kilometer. In comparison, London has around 5000 residents per square kilometer. However, we do have a few green zones where farmlands, forrests and reserves dominate the scenery. I live on the "outskirts" of our city where such a bufferzone resides. A few minutes walking and I trade concrete for woodlands

So, I'm used to a lot of people around me. But London felt worse, especially with all the big lighted billboards, American style huge shops, rows upon rows of people all wanting the same thing and utter chaotic traffic due to all the work that was done for the Olympics. I really felt a bit depressed while standing there. The Hague can be as bad, but without the pressing feeling. Am I making any sense?
Our experience with the tube in rush hour on thursday and friday wasn't as bad as the Picadilly Circus stop on saturday around closing time. I shiver at the situation you describe. We have that kind of situations here too, but without railway personal helping to push people in so the doors can close. I was actually pleasantly supprised by the smoothness of the tube services. They're far supperior to what we have here. It's pretty bad here. Services during autumn and winters are so bad the government is involved as people were stuck for up to 8 hours waiting for some kind of information about the service. Imagine London, rush hour and no tube in sight for 8 hours...
I was kind of disappointed in the fees which were asked for entrance to some of the sights. £19,80 for a ticket into the Tower complex, £18 for St. Paul's and a similar figure for Westminster Abbey. I found that a bit much, especially as I had a days worth of 'ooohs' and 'aaahs' for less in the Vatican! Entry to Saint Peter's Basilica was free (read that London, free!) and the Vatican Museum with entry to the Sistine Chapel was around £20. That was worth every penny. Also, a day in El Alhambra, Granada (Spain) including some magnificent gardens costs £16. And believe me, you need that full day! So, you can imagine our disappointment in London. Don't fancy art galleries that much, don't like the ambience/feeling of going there. Museums can be very interesting, but the crowd I was with didn't share the sentiment
Mark