Amongst UK freshwater fish I would put over short distances, the pike is number 1, followed by rainbow trout in good condition, blue trout particularly.
Long lean wild carp used to be pretty good, although I think there is a dearth of these now more's the pity.
Of the freshwater species I have caught in the world, Tigerfish are not bad, Yellowfish are really exceptional and small mouth bass can motor too.
But nothing in freshwater can touch a few of the saltwater species. Yellowtailed Kingfish, Queenfish, Tailor (called bluefish in USA and shad in South Africa), Bonefish and certainly the mullet which migrates into our waters in the summer.
But probably nothing in terms of acceleration from a standing start can beat a Springer or Ladyfish - Elops machnata. These things do not grow big, maybe no more than 8 lbs, yet the speed that they can reach in a few seconds is phenomenal.