For NFP trading, EURUSD, GBPUSD, USDJPY and Gold are the best assets. The latter is good because price reaction is usually more pronounced.
the success of scalping never depends on your trading pair , it completely depends on your powerful money management.
The most suitable pair for scalping, in my view, is the EURUSD because its volatility is lower for most parts of the trade and with a suitable broker like Fxview or FP Markets, the spreads begin at 0.1 pips.
I believe, there is no specific answer on this question! BY the way, nowadays I’m enjoying Gold trading pair for scalping; although last year EURUSD was my 1st choice for scalping trading!
For beginner scalpers, the best pair in my opinion is the EURUSD because the liquidity is higher and the volatility is lower. If you scalp with an ECN broker like ICM or FP Markets, it can be an advantage due to their tight spreads.
I mostly scalp EUR/USD and GBP/JPY. Scalping is an aggressive form of trading and choosing right currency pairs is very important.