It's not just that the vampires are sparkly. It's also poorly written, poorly characterized, poorly plotted, uninteresting, unoriginal and often unintelligent. The films are worse as they are also poorly acted, poorly cast, poorly directed and feature pathetic effects. I'm sorry, I know you're entitled to your opinion, but they fail every single test of a book or films quality.
Yes they are poorly written, doesn't matter who you're aiming it at, there are basic tenants of writing and she misses them all. You want a better writer aimed at teenage girls in more or less the same genre (IE: Fantasy)? Go track down some books by a woman named Tamora Pierce. Her Song of the Lioness Quartet and Wild Magic Quartet are her best. They're romance-based books aimed at teenage girls, but she has an interesting prose, well written characters and a unique and engaging world.
And I'm sorry to (evil) harp(o) on this (everyone who got the evil harpo reference, you're awesome), but if you're going to take away what makes them Vampires, why call them Vampires? Seriously, all they adhere to is the whole blood drinking aspect. Rewrite a few things, like why they need to drink blood, and call them something else and no one would think they're vampires. Because they're not.
In conclusion, you're entitled to your own opinion, but if you like teenage vampire romance and would like to see it better in every way, I recommend you check out a TV series entitled Buffy the Vampire Slayer. Not the movie. Never the movie. The TV show.
So to summarize: Yes they suck by the standards set down by...well everyone. If you want something better in the same vein, check out Buffy the Vampire Slayer and anything by Tamora Pierce.