10. Nina Dobrev
This "Degrassi" alum is capable as sullen teen Elena and really shines when playing the vicious bloodsucker Katherine. We love her in period garb, wickedly teasing and taunting the Salvatore brothers.
9. Branching Out From the Books
One of our big concerns at the outset of the TV series was the limited scope of the books it was based on, especially since the pilot covered much of the ground from the novels. But subsequent episodes have been anything but thin.
8. Plenty of Fanged Foes
When the show kicked off, it featured just two vamps: one good, one bad. But as the first season went on, we were introduced to an entire vampire community to love and hate (mostly hate), along with plenty of folks who want to kill them all.
7. Likeable Humans
Mystic Falls boasts plenty of ordinary humans who are anything but boring afterthoughts, from Elena's brother Jeremy to the adorable teen Matt to Elena's sassy gal pal Caroline, with no shortage of character development.
6. Interesting Mythology
The entire town of Mystic Falls has a weird Sunnydale vibe about it: evil just flocks there. And the more we learn about the quaint small town, the more twisted we find out that it really is. We can never wait to find out what skeletons are hiding in all of those perfectly decorated closets.
5. Stefan Salvatore
Stefan could've been as wooden as Edward on "Twilight" or as stuck in the past as Bill on "True Blood," but instead actor Paul Wesley has crafted a wonderfully conflicted character. His Stefan is not only madly in love, but he also can be evil, more than a little bit protective, and not at all above lying.
4. It's Scary and Creepy
A supernatural show shouldn't be all talk — it should have its share of terrifying moments, which this one delivers via freaky scenes underground and in the dark woods, filled with blood and unnatural evildoers.
3. More Than Just Romance
Elena may be dating a vampire, but she's not begging to be bitten so she can become his eternal girlfriend. Her backbone helps make this show more than the stupid supernatural love story it could just as easily have been.
2. Tremendous Pacing
Something major has happened on the show almost every single week. Weaker shows drag out plot points for episodes on end, but "The Vampire Diaries" resolves those storylines in a mere forty minutes and then blows us away with something new.
1. Damon Salvatore
Ian Somerhalder has been a revelation on this show and it's just a pleasure watching him relish playing a complex bad boy. His Damon is funny, charming, and deliciously sinful all at once, forming the glue (or plasma) that holds the show together and makes it bloody good.
source: http://tv.yahoo.com/blog/the-vampire-diaries-why-it-might-be-tvs-most-addictive-show--1034
