I drink around 6 to 8 pints a day. They say the more the better and I agree. Some days it easier than others but I don't get hung up on it. It's part of why the diet works but not the be all and end all.
As long as I get at least the minimum 4 pints I'm happy. If I've had good losses then I've probably drunk alot that week too.
I drink a minimum of 4 litres every day.... have an extra litre if i can fit it in without needing the loo all night! 4 Litres was the min on LL so by time i switched to CD i'd got used to it and thought it best to just keep it the same.
I used to have 4.5 litres, then I was ill and couldn't manage it all and not only prefer it but have lost more weight. So now I make sure I have 2.25l and any more is just on an as required basis. It also means I don't have to get up in the night any more.
I tend to drink around 4lt a day but I don't get too hung up on it, it has just become a habit now. Weight loss definitely seems to increase with more water though.