Depends on your trading style but there really is no “best”. If you’re a Price Action trader, you don’t have to limit yourself to just one or two pairs. I check about a dozen every day for set ups because the principles apply to any pair really. It’s just you want to focus on pairs that have enough volatility to move in a timely fashion so you’re not over-exposed in the markets. Additionally, you may feel comfortable dropping to another time frame. I trade on day charts primarily but 4h perform similar but have many more tradeable opportunities. So since there hasn’t been a whole lot on the day charts recently I’ve dropped to 4h for the time being.
It completely depends on your strategy whether or not this will be a good idea. And if you do trade Price Action (since I saw you mention using candlestick signals)… know that once you get under 4h charts the signals can be more misleading due to less information being presented in each stick. So you really want to hunt for the very clear, obvious set ups.