Actually, as far as I concerned, there are no best currency pairs for trading. There are only those which can help you to generate money. They vary from day to day, and of course, they vary from the current situation on the market. For example, if you see that news about jpy was released, you probably can think about how this news affect currency pair usd/jpy. Here you make conclusions and decide whether it's a good time to trade this pair or not. Every currency pair can possibly bring you money and experience, it depends on the time when you enter the market.