How is your tap water?

Can you drink your water straight from the tap or do you need to filter it first? Or is it so bad that you use bottled water?

I've heard American tap water tastes bad though I'm not sure why.

I imagine the best tap water would be from Iceland or the Nordic region.

Here in Britain, the further north you go the better it gets but it's nice and cool and drinkable throughout the whole of the Isle.