Ugh, I know the feeling. I started out being open to most things (then realized that Sam is my fandom bicycle and I'll read almost anything he's shipped in which... isn't much in this fandom unfortunately), and when I ran across a Sam/Gabriel fic I went O.o... Read it and it was good, then read another, and it was a guilty pleasure because I was reading (and planning on writing) mainly Sam/Dean. THEN I COULDN'T STOP READING IT and they were the pairing that gave me the motivation to actually write something.