Um, instead of giving suggestions for hedging, I want to make a couple of points. If you have a long garden, putting hedging down both sides will only make it look longer and narrower. Do you want hedging to avoid putting up a fence or barrier? Is there anything in the garden currently? Which way does it face (north, south, whatever).

Hi Bamboo,
Fencing would be an option but I just wanted something a little different... We face south and get sunlight all day. The garden has a slow incline and has been tiered into 4 sections.

personally I'd go for a mixed hedge of british natives such as blackthorn, hawthorn, hazel, hornbeam, beech, holly, spindle, wild roses, honeysuckle intertwined through it too etc.

or there are berberis, cotoneaster, escallonia, laurel, acuba, holly, etc

I'd avoid having the same all down the length of a long garden. I'm slowly removing our long privet hedge and replacing it with shrubs and the difference is amazing. An easily maintained hedge could be Lonicera nitida - there is a gold leaved variety that's quite cheerful though the green one is rather dull. It depends too on whether you have a relaxed country type garden or a formal housing estate type one, and whether you are planning a narrow or wide border in front of it. Some hedges eg beech get very wide as the age. and consider clipping - are you prepared to gather up and dispose of prunings from thorny plants?

Blackthorn is endemic to our part of Wales and it suckers like mad here, so I'd avoid that for both the suckering and the disposal problems. It's fine if you have a field on the other side but not so good for a very formal clipped hedge.

Pyracantha can make an attractive hedge with both flowers and berries and seems to survive quite harsh clipping, but you still have thorns.

Put this on twice but can't delete it, only replace it!