The best kind is the kind you make yourself. You would really have to research the companies to see how they make their silver and spend infinite times more money than what you can make yourself. You would also probably be buying an 8 oz. bottle, and if you want to take it daily, you could easily drink up to 16 oz. a day of what you make at home. Don't waste your money on CS when you can pay up to just as much for an 8 oz. bottle as you can for a generator that can make gallons and gallons so that you can sip on it all day every day.