You can always get free titles from Amazon
Go to kindle store/books and you will find the top 100 in two charts, one paid and one free.
Have a look through the best-rated, read the reviews and try a few
Then there are loads that are under £1 as well, often really good ones.
The thread in here 'A good buy/free' is almost all Amazon kindle deals - sign up for the kindle deals emails, it only takes a few seconds to see if there are any you fancy.
The deals are often free or 99p for a limited time and can be brand new releases.
Have a look on amazon at authors you like, sometimes one title will be cheap or free and others full price.
Do you really never buy books then Gal?
Before both of us had problems with 'real' books, we'd both buy loads at charity shops and car boot sales. Charity shops often charge £2 so I'm more than happy spending 99p or £1.99 for the kindle editions.
Edited to add - you'll find virtually any 'classic' you can think of for free, the first book I downloaded was Pride & Prejudice