One thing that has bugged me about Green Bay's helmet is the "G". Where is the "B"? Green Bay is two separate words and both initials should be present on their helmet. The Giants don't use a sole "N" on their helmets, right?
On this design I went with one of their older logos, obviously, then added the much needed "B". Being one of the older teams in the league, I felt the white helmet conveys more of a retro look than cheese yellow.