Vampire Academy Series by Richelle Mead
It took me a while to start this series but I really didn't like the original covers but I ended up getting it free in which I then read and fell in love with it so I had to get the rest of the books which where all the same until Last Sacrifice came out.
Last Sacrifice ended up being the red covers like the ones above and I absolutely fell in love the the cover. I think in the future I will end up getting the series again in this version as I just love them!
I love the way they are simple with a solid colour red in the background and then a black pattern in the foreground it looks so effective.
I also love the title which is also simple apart from the first letters of the series which makes it look so elegant and you just know that it a part of a series which I think some series miss.