Preheat the oven to 250°F.
In a medium saucepan, combine butter, Worcestershire sauce, and everything but the bagel and ranch seasoning. Cook, stirring often, until the butter has melted and the mixture begins to simmer.
To 2 roasting pans or large baking dishes, divide evenly and mix together Goldfish, Cheezits, Bugles, pretzels, corn Chex, rice Chex and peanuts.
Pour the butter mixture on top and toss until coated well.
Bake for 1 hour, stirring every 20 minutes. Bake an extra 20 if you like them extra toasty.
Remove from the oven, and while the mixture is warm, sprinkle on garlic salt. Once the mixture cools, add M&Ms.