I originally began reading the series as a result of the TV series. However, by the time I began reading these two I had long forgotten the TV series and was really loving the books. The end of the second book left me wanting more, thus I was really eager to see what was to become of Elena.
I thoroughly enjoyed reading them. You see Damon's character develop further, the strength of Stefan and Elena's relationship, and you see the brother's join forces to fight against a larger evil, which is certainly refreshing.
Other reviewers have compared these series to the Twilight series. I believe that you should take both books for what they are and certainly not compare them, they both have their strengths and weaknesses. I have enjoyed both series enourmously and certainly recommend anyone to read these books, you won't be dissapointed.