Oh, god, I LOVE this topic.
Just came back from August WDW Trip. Consensus on Water Fountains:
- Magic Kingdom = disgusting
- EPCOT = delicious and ice cold! definitely the best of all parks!
- Animal Kingdom = maybe one or two cold fountains; the rest..
- MGM Hollywood Studios = depends. the one halfway through the line for TOT is ice cold and awesome! you have to search 'em out, here. but you can definitely get the good stuff.
Yeah. I was "that person" refilling my bottle, too cheap to buy a new one.. :P