1. Its numerous famous landmarks: the Universities of Oxford and Cambridge, Shakespeare's birthplace (Stratford-Upon-Avon), BigBen and the whole of London, the Stonehenge and the Roman Baths, among others.
2. It is in the center of the world's aviation industry. Anywhere in the world you may be, you will easily find a flight to Heathrow, the busiest airport of the world.
3. You have tons of budget airline choices which could take you all around
4. They ALL speak English! And with cute accents, to boot!
5. The locals are generally polite and helpful to tourists.
6. The local government took out its big wallet and gave £1M to help support rural tourism in England. VisitBritain, a national tourism agency, will primarily help promote rural destinations and attractions. They will be making sure that your choice to visit Britain will definitely be worth it.
sources: Hotel Travel News and WikiTravel