Subreddits in the video in order of appearance:
http://www.reddit.com/r/politics
http://www.reddit.com/r/programming
http://www.reddit.com/r/AdviceAnimals
http://www.reddit.com/r/DotA2
http://www.reddit.com/r/starcraft
http://www.reddit.com/r/london
http://www.reddit.com/r/unitedkingdom
http://www.reddit.com/r/europe/
http://www.reddit.com/r/firefly
http://www.reddit.com/r/thewire
http://www.reddit.com/r/technology
http://www.reddit.com/r/vexillology
http://www.reddit.com/r/vexillologytechnology
http://www.reddit.com/r/awww
http://www.reddit.com/r/ukpolitics
http://www.reddit.com/r/battlestations
http://www.reddit.com/r/birdswitharms
http://www.reddit.com/r/hitlerinsocks
http://www.reddit.com/r/explainlikeiama
http://www.reddit.com/r/InfrastructurePorn
http://www.reddit.com/r/prisonarchitect/
http://www.reddit.com/r/apple
http://www.reddit.com/r/mildlyinteresting
http://www.reddit.com/r/changemyview
http://www.reddit.com/r/askscience
http://www.reddit.com/r/iama
http://www.reddit.com/r/meetup
http://www.reddit.com/r/Assistance
http://www.reddit.com/r/secretsanta/