I always drink tap water here in the Netherlands, in the US where I have been (Houston, New Orleans, Boston, Long Beach) the water just tastes like it came from a swimming pool. So much chlorine, I couldn't drink it. In San Fransisco it was relatively ok though, still a faint chlorine taste but drinkable. I understand the difficulty of maintaining such a large water distribution net but I certainly switch to bottled water when I'm in the US.

I do like the fact that you can get free water almost everywhere, there was often a large can and cups on the bar, free to take. Here a tap water is sometimes as expensive as a beer (in a bar obviously).