It's very difficult to pick the 'easiest' A Levels, it really depends on each individual. All A Levels need a lot of work! I did French, Spanish, Geography and Maths at AS, so I can only relate to AS Maths being a pain, but if you are considering that type of degree you must feel comfortable with it!!
The best advice I can give is do what you enjoy doing, that makes studying it a lot easier. You will also need to think about which subjects fit best with the requirements of your degree course, because the work will be worth it if you can get into the place you want doing what you want!
Hope this helps a bit!