I think GBP/USD and GBP/JPY the good currency pairs for trading as they are easy to predict and offer good liquidity.
I think major currency pairs are the best choice. Also traders must choose currency pairs that they understand the best.
The USD/EUR pair is often the most liquid currency pair in forex and is therefore the most profitable. This pair is typically the most liquid and volatile because it has the most traders and trade volume.
For me in the UK I like to trade EURUSD and GBPUSD as I can trade both the London and NY sessions and I find these pairs work well for those periods of the day.
EURUSD is most usable trading pair and all kinds of trade like to trade due to its comfortable trading spreads.