As far as I know, all the flights from the US to England are overnight flights. I wish there were some daytime flights!
As far as the best airlines, I find that non-US based airlines are less profit-driven and more likely to have good food and good service. However, you have to be careful. You can book with Air France, for example, and find yourself on a flight operated by Delta, with crappy food. They have alliances, and often don't tell you who is actually operating the flight. Lufthansa is good. The airlines regularly voted the best in surveys are the Asian and Middle Eastern ones.