Major currencies yield more profits because they are more liquid and less volatile than others. It also depends on your trading strategy, if you are a scalper or a day trader you can really benefit from the tight spreads on these major pairs.
I like trading with major currency pairs since they’re more liquid and stable than other pairs. All pairs require different strategies. If your strategy is good with one pair, then you can say it is your best pair.
The best currency for me is EURUSD and JPYUSD. I prefer them mainly for their higher volatility, and the spreads are lower.