Based on the latest analytical reviews from the broker amarket, I can say that for me now working with CND / USD is quite promising
EUR/USD is the best pair to trade because of it possesses great liquidity and tight spreads due to huge trading volume.
I think EUR/USD and GBP/USD are the best pairs for day traders because spreads are generally low on these pairs.
I still think that it is better to trade EURUSD. I know that the volatility decreases during some period of time, but still it is one of the most liquid currency pairs on the market. However, if you want to have huge volatility 24/7, i'd recommend you start trading cryptocurrencies. FIrst of all, they are traded 24/7, so there will be no periods of doing nothing for you. You will always have the opportunities to make profits. Second of all, cryptos are much more volatile than traditional currencies. It means that you can earn big, or at least bigger than trading forex. However, you should bear in mind the fact that volatility not always implies liquidity. If you trade forex, you can see this trading minors. So, I recommend you trading some popular cryptos like btc or ethereum in order to have the possibility to close the deal in short time period. You should know that cryptos are different from traditional currencies, so you need to learn this financial instrument and study it very attentively, otherwise the volatility may kill your budget.
I prefer more fluctuations for scalping, so I play around most of the time with USDJPY , pays off well when the market is volatile.