I'm from north essex so have a obvious affinity with here, I lived in west sussex for some years and also love that part of the country., other than those I love devon and cornwall, both fantastic places and pretty much the only places you can see and swim/dive in a clear blue sea in this country.
The border region in scotland just took my breath away the first time I saw it, as did the peak and lake district.
If you have never been to wales then you really should, snowdonnia (sp?) is buy far the best for scenery