I really can't choose between three. Certainly all 3 are a quantum leap ahead of anything in the UK
1. Popeye's Bilge rat Barges, IOA. Best themed rapids ever. Never go through a carwash in a convertible!
2. Dudley Doright's Ripsaw Falls. Awesome theming. Best log drop of them all.
3.River Quest, Phantasialand, the Steroid filled Rapids oddyssey, all from a site as big as a shoebox.
I like Valhalla, butit is just too much of a compromise because all of the effects are never working. it's also a bad location due to it being grim up north, weatherwise.
I like Stormforce 10, Its certainly original but lacks rerideability.
I like Tidal Wave, but on a warm day, when a ride is needed, up comes the Tussauds 'stuff the punters, a 90 minute Q is perfectly acceptable'.
I can really name any other UK water ride worthy of any positive comment although I hope to be riding Hydro for the first time soon.