When I wrote my first book, Letting Go, it was in first person. I told the story from Sabrina's POV. When I got that first acceptance letter from Siren Publishing (still hearing angels singing,) they made it conditional that I change the story to third person and add in Jonas's point of view.
In the meantime, I've recently returned to writing from the first person perspective. Surreal Neal, the sixth book in the Awakenings series, is written in first person. I learned my lesson from Letting Go, however, and the chapters rotate between Sophia, Drew, and Neal. If you're not familiar with Hanging On, you can still pick up Surreal Neal and enjoy it, though I think you'll enjoy the second story more if you've been with Drew and Sophia from the start.
In the meantime, I started a new series. It's a mainstream romance (with heat--don't worry, there's still sex) that's written entirely from the heroine's perspective. She has the most to lose in this series (Kiss Me, in case you were wondering.) I wrote them almost like a diary, and I took inspiration from the classics. Lacey (main character) speaks directly to her readers, at time dropping the figurative fourth wall. In the second book, she does give the epilogue to the hero so that he can vindicate himself a bit. He doesn't even bother with a narrative style. He speaks directly to the reader in a conversational tone. I think it's the best thing I've written yet. It's a two-book series (so far), and it's the first series I've ever contracted where I had a deadline for a book I hadn't yet written. It'll be out sometime in 2014 (I hope) from Omnific Publishing. (More to come about that later.)