Drinking water is good for you because unlike other drinks water is the only drink that does not contain sugar in it. Water helps you lose weight, but it doesn't have any flavour that's why people often drink Powerade or other sports drinks because they have flavour.
Water can help you overcome some big diseases such as heart disease. Clean water can help you overcome diseases but dirty water can actually give you Water borne diseases like Giardia and Cholera. Luckily in New Zealand our water is usually clean. The country most affected by bacteria in their water is Africa. Water borne disease have caused over 1.8 million deaths annually.
It is possible to drink too much water. If you drank too much water you would not be able to control your bladder and would need to go toilet every 1-4 hours. If you drink a lot of water during a meal it can make you fill up faster.
Therefore my opinion on drinking water is that it is good for you. Even though it has no flavour it is still healthy and is one of the healthiest drinks in the world. If I was in a different country with water that had bacteria in it my opinion might change.