Viburnum tinus or for alternative viburnums click on V in Goypedia (A - Z at the foot of the page). There are 237 photos in that file at the moment.

Privet as such is usually used for hedging and has insignificant flowers, V tinus as Scotsgran says is much prettier

Osmanthus x burkwoodii - classier

A bit of a variation, but have you considered Ceanothus?

Evergreeen, lovely Blue flowers and you can get various types which varying leaf size.

If you want just one try a hypericum Hidcote. It can grow into a large bush eventually. It is almost evergreen,same as privet, depending on climate and has big saucer shaped flowers from June onwards. It is also tolerant and dead easy. Mine has reached about five feet high and across in as many years but you can cut them back to about three - but of course you cut the leaves off then and have to wait for the new growth. Never seen them used as a hedge but don't see why not.
If you go for the ceanothus remember it needs a sunny spot sheltered from the wind.

I like Escallonia too, especially apple blossom

Thanks for your learned suggestions, vey much appreciated! I'll let you know which I choose. Thanks again.

Saw a beautiful spirea yesterday - covered in white blossom. Think it was bridal wreath. Absolutely stunning.

Ligustrum .... if you let them grow they will reward you with flowers that have a scent, more the merrier i say, i have around a dozen and i always look foward to the flowers (and so do the bees & butterflies).