Best green chili flavor is just before it starts to turn red, so I would pick the first one when you start to see color. They make a passable chilipowder when red and dried.
I eat most of my green chilis on cheeseburgers and in omlets. Nothing is better than a southwestern burger. I roast them under the broiler to blister the skin and then freeze. Frozen with the skins on you can break a few out of a gallon ziplock frozen pack for use. They peel easily under warm water when partially frozen.
We like to split them lenght-wise and seed and vein them. Mix up some cream cheese with spices, whatever you like, and maybe some bacon bits or canned tiny shrimp and then stuff the pepper halves. Lay them on the grill til done and enjoy! We get rave reviews when we have friends over for dinner.