I didn’t see everything due to my limited time in London, but I got to see a lot and if I had a little more time, definitely could have gone through the entire museum without a problem. I did make a point to see some important works such as Leonardo’s Virgin of the Rocks.
When I was there, the Olympics were still playing and they had a large screen TV out front with them playing.
Admission to the museum is free, which is a huge bonus since London is so expensive!