Concur with the sentiments expressed by many thus far.
DW the stand out park for me, a multitude of different ride experiences and a good, full day of activity, as well as having a nice range of 'other' experiences; animals, Tiger show, Outback show etc.....
Of the other parks I rate SW higher than MW because of the variety on offer and I am probably harder on MW because I usually find their shows to be quite mediocre.
Water park wise, I see WnW as being a superior park, I must admit I look at WWW as being more of a nice add-on to DW rather than a park in its own right.