Like you some of my favorite fics were some I read knowing nothing whatsoever about the fandom... I usually found them either through recs, or while going through the fics of a favorite author (Astolat and Maldoror-gw were respectively my introduction to Person of Interest, The Whitcher, Transformers, Fast and Furious, Gundam Wing, One Piece and probably a few others...) and authors like Bendingsignpost or Dsudis also are usual suspects in this kind of things. :D .
Also a small bit of canon and a lot of fandom osmosis were enought to get me through many SGA, Teen Wolf or Supernatural fics... ^^
I agree that often longfics and canon AU are better for that kind of things, because they are fleshed out.