Ninja has hit a home run with its Ninja Thirsti Drink System.  It doesn't take up a lot of room (fits on my little table with coffee maker without crowding it), its simple to use, fun to check out the flavor blends.  You can blend two together or just do one at a time and you can easily choose your carbonation strength (from still to low, med, or high) as well as flavor strength.  It is very easy to use and fun to experiment with, as well as making good drinks.