I have also read some of the original Vampire Diaries series, by L.J. Smith, and I have to say I don't hold the same love for the books. Perhaps if I had read them in the 90s when they originally came out, I'd have a different view of them. After watching the show, reading the books was like going back in time, in a bad way. Most of the character names and some of the setting is taken from the book, but there is SO much that is different, it's almost distracting to read. My biggest complaint is that the book reads like it's from another time. Many of the names that were changed were old-fashioned and it was obvious that the time-period is twenty years ago. I read the first two volumes and it was okay, but by the third volume, the book got so ridiculous, I had to put it down.
There is also a new series of Vampire Diaries, which follows Stefan's perspective starting when he and Damon become vamps. I think this would be a more interesting read being that it follows the characters as we know them and through the backstory that was set up in the show, which I actually like better than the original. I'm looking forward to reading them over the summer and may just buy the paperbacks so I can have Damon's and Stefan's beautiful faces on the covers!