What height hedge do you want, what is your soil type, is the position shaded or sunny?

Yes as bornagain asks there is more to it than that. What is it for screening/privacy, shelter maintaining boundary, or for reducing the road noise/sight, how wide/high, prickerly flowering, winter colour, attract wildlife, life are you going to train it,and do you want to cut it 2-3 times a year? will your neighbours be concerned. Anwer this and the members will have a real good idea on what to offer you.

you cant go to wrong with escallonia, evergreen dense and flowers too.

I'd go for Berberis darwinii or Photinia fraserii, though the latter doesn't like lots of cold wind much, and you won't see the flowers cos you'll be cutting it all the time. Pyracantha's another option, although this is very thorny (Berberis only has prickly leaves). All of these will need some sun. If it's in dark shade, you've only got one choice - prunus laurocerasus, but it gets huge.

I'd go with Seaburngirl - lovely choice of colours too.