My favorite YA series of all is the Mortal Instruments - Cassandra Clare. It was one of the first YA books I read after Twilight and could not believe I had found something I loved as much so quickly (I had read Twilight multiple times before I could move on too. There are other ones I really like but this one is at the top. If you want YA fantasy/romance I recommend The Iron King, Hush Hush, and LOVE love love Shiver and Linger.
I love a good love story (Triangle is never bad), but not over the top mush. I like some angst, and mystery as well...