Right now, I alternate between a filter on the kitchen tap and occasional bottled water. I'd love to put in a 'better' filtration system, especially one that removes fluoride (that seems to be distillation?) but this is about the extent our lease and finances allow us right now. (Darn it.)
But like someone else noted, I can *definitely* taste the difference between our tap and filtered water. So much so that I can tell when the filter needs replacing before the indicator warns us.
Right now, it's better than tap, so ~shrug~
Oh, and check into shower filters as well. Skin is the largest organ and every time we shower in tap water we're just soaking up all that wonderful gunk from the municipal 'safe' water supplies.