Drinking water as your default will help your hydration levels. You can of course drink alternatives, but ultimately it is their water content that will make the difference. If you are out doing sport, then you may want to consider a sports specific drink, but only if you require the electrolytes.
Caffeinated drinks like tea, coffee or other soft drinks will all hydrate you, but not to the same extent as water. Caffeine acts as a diuretic, meaning that it will make you pee out water more quickly. If you want to drink caffeine, limit your daily intake to 1 or 2 cups a day, and consider switching up your usual cup of coffee for lower caffeine option such as some teas or decaf.