What is the best fast growing plant for forming an hedge?

Where i live i have a big garden with hardly any fencing and very nosey neighbours,i've been trying to come up with a design for my garden,but the main thing is the hedging as i have a two year old daughter and at the bottom of the garden is a six foot drop onto the public pavement i've been given 7 buxus,but i know these are slow growing,3 cypresses of a very light green colour and 3 Japanese maples i'm not sure if these are any good please could you recommend anything?