Stanley cups have surged in popularity recently, becoming the must-have water bottle to get your hands on. Far from just a trend, the Stanley bottle delivers on its promises, keeping your beverages cold all day while helping you increase your daily water intake with its generous size. The hefty price tag can be a little bit off-putting, but that's where Amazon comes in. Kicking off their huge spring sales week just yesterday, the online retailer has discounted hundreds of must-have items, and