What is your favorite Grateful Dead song?

I received a huge response from my "favorite Rolling Stones song" post and I will be listening to the Stones for a month to understand the depth of their catalog. Thank you to everyone! Now lets hear what is so great about the Grateful Dead.? I know people traveled all over the country with them as they played and I know the song Trucking but not much else. Did people follow them just for the drugs and how did the followers eat, sleep and stay alive haha? Maybe I am being ignorant but I want to know