I like the show, too.... but only because of Damon.
He's super awesome.
His brother is a cry baby, and there is no chance in hell that a real Elena would ever pick him.
The books are okay, but nothing spectacular.
Haven't seen the show, but if you're going to read the books, stop after the first 4 (The Awakening, The Struggle, The Fury, Dark Reunion) or possibly even after just the first 3. The ones that Smith has been putting out lately are beyond godawful, to the point where the publisher has actually taken the series away from her and is having the remainder of the books ghostwritten.
If you like Smith's work and vampires, though, I'd check out her Night World series. It's uneven and only some of them have vamps, but I prefer the Night World books to Vampire Diaries. (But warning: she's never put out the last book in the Night World series, Strange Fate, and the release date keeps getting pushed farther and farther back. Not to mention, with the drop in quality of her recent work, I don't think the series is going to end on a well-written note. OTOH, even the worst of the Night World stuff is much, much better than Twilight.)
As for the Anita Blake novels, they've gradually been turning into porn without plot. Would not recommend (or would recommend stopping long before current point.)
I'll second the recommendation for Anne Rice's first four books, as well. Again, that's a series that starts deteriorating in quality after a while.