I can't remember my first fic. It was so long ago and I've read so many. I remember after the third book came out I was looking for this pairing. I'd read a few interesting Snupin fics, but I couldn't find any Snarry at the time. Then I joined the Snapeslash yahoo group, which featured pretty much all Snape pairings but often leaned towards slash. Eventually the Snarry fics started trickling in. It's really frustrating when you realize you love a pairing you had been looking for, but you can't find anything more on it.
So, I guess I was a bit too early to the party. And I think now the first few fics I read weren't so memorable except for the fact they were Snarry. The writing was okay, but it wasn't amazing or memorable for me. It still showed me that I liked the pairing, though