6. Reddest red light district
Pat Pong is watered down and clogged with tourists. Nana Plaza is big, but too crowded.
But Soi Cowboy (BTS Asok; MRT Sukhumvit) is big enough to have fun, and small enough that you won't lose any friends.
Its neon glow can be seen for miles around, and a quick drink with friends here can turn into a night that few remember but no one will forget.