Searching for Summer Sun

My boyfriend and I really want to escape london and go and relax in the sun on a beautiful sandy beach somewhere. Ideally we would like to leave this weekend or early next and go for 3-4 nights!!
We have 2 problems...
1. We are on a very tight budget
2. There are too many choices!
We have just from Australia and the number of countries and options is making it really hard for me to make up my mind. This will also be our first trip out England.
Where can you suggest to go that is cheap to get to and cheap to stay at. We aren't looking to party or go crazy, just chill somewhere beautiful - sunbaking - swimming - bit of hiking maybe...