Every currency pair can be good for a trader if they know how to trade it. There is no such thing as a universally good currency pair - it depends on one's knowledge, strategy, available time, experience and personal preferences, so it is all very subjective. That said, most newbie traders, at least, stick to the most popular currency pairs because there is a lot of free information easily available about them online and move onto the exotics once they learn how to trade those.