We currently use a water fountain for our cat. We have had dishes before, but my father-in-law actually bought us a fountain, since he said it had worked well for his cats and seemed to encourage them to drink more. We also found with our cat that once we set up the fountain-style water dish that he seemed to be drinking a lot more. Something about the running water has always interested our cat, so it's been a beneficial change in my opinion.
The only real issue we have with the use of the fountain is that our dog loves to drink from it too, so we're constantly having to clean it out, far more regularly than the directions recommend (he seems to get it very grubby and dirty for some reason!) but really, that's a small inconvenience for the reassurance of knowing my pets are drinking enough water. Plus, I think they just look nicer in our home than a standard dish does.
