Discover which fast-food chains offer the best iced coffee according to real diners. As someone who lives off of iced coffee, finding the right mix is a science. When it comes to iced coffee, here’s what other caffeine enthusiasts are saying about some of the best locations you could hit up for deals, great menu items and more importantly, a quality iced coffee on a hot summer morning. McDonald’s6254a4d1642c605c54bf1cab17d50f1eMcDonald’s iced coffee has built a fan base, not just around flavor, but for affordability. “This is my third Snickerdoodle Iced Coffee during this promotional period.