Who are the main songwriters for the Grateful Dead?

Answer: The main song writers for the Grateful Dead were Jerry Garcia, Bob Weir, Phil Lesh, Robert Hunter, and John Perry Barlow.  

Typically, Jerry Garcia and Robert Hunter worked on songs together, and Bob Weir and John Perry Barlow worked together.

A lot of song credits are credited as Garcia/Hunter, or Weir/Barlow.