Yeah, like everyone else said The Hunger Games trilogy is ok.
-Fallen series by Lauren Kate (again they're ok, slightly disappointing from the cover)
-House of Night series (I really don't like these books because the main character is absolutely a Mary Sue and she has sex with like 2432 people but she's still somehow The Chosen One by their vampire goddess woman because 'everyone makes mistakes', but other people seem to like it)
-Uglies series (these are really good, no vampires but they will blow your mind)
-Darke Academy series (I think)
-Vampire Academy (bit more vampirey)
-Vampire Diaries (you've probably seen it on TV, but it's the story of a reincarnated girl or something that spends the entire time deciding whether she wants to be with one guy or the other guy)
-Beautiful Dead
-Mortal Instruments (they're making these into films, you can check out the City of Bones trailer if you want to but I suggest not until you've read them all because then it'd spoil your imagination of the characters)
-Hush Hush (I've never read this, but it seems to have good reviews)
-Peter Jackson's Lightning Thief series (these are amazing, less romance but you'll regret not reading them - the first film came out like 3 years ago)
-Inheritance series (I think that's what it's called, but the first book is called Eragon and it's written by Paolo somebody lol. The romance is a little less obvious, but still there. There's a film for this as well - it's good if you're into HP)
-You can check out other books by going on Amazon and searching for Twilight then looking at what other people bought, they're usually books that are similar
-EXTRA: If you're feeling really romantic, you can read any one of Nicholas Sparks' books, but if you want serious action you can read Eoin Colfer, Phillip Pullman, Chronicles of Ancient Darkness series etc. The last one is a bit weird, but I remember reading it when I was younger and was just fascinated by how good it was.