Well bugger me, Extra Ball didn't list WH2O.  

For me, a very overrated game is The Getaway II - High Speed.  I have owned one and sold one.  Take the Supercharger out of this game and there isn't much else to do.  Then you can only watch the ball whiz around the Supercharger so many times before it gets very boring.  The only reason I regret selling it is that I sold it too cheap.