Since most currencies are coupled with USD to make a pair, 50% of volatility of any pair is that of USD. So generally speaking, EURUSD, GBPUSD and USDJPY share the majority of moves.
As I've been observing, the economic indicators moves the price. So the more frequent the data is released, the more frequent the pair moves, in other word, the higher the volatility is.
EURUSD is the most volatile pair, because EUR is affected by more countries than other pairs. For instance, GBP is affected by only UK, and JPY is affected by Japan. Since it covers many countries, EUR got affected by every news released in Europe!
That's why you often see EURUSD is choppy or has broken trend while USDJPY and GBPUSD are having nice trend. (Open up all 30M charts and see from 25 Sep to 02 Oct for yourself)