I meant to weigh in on this a few weeks ago, but I've been a little tied up recently.
I feel that I've discovered quite a bit of stuff at my local FLGS. I would probably never have discovered DeepWars if I hadn't seen it at Gamer's Haven in Colorado Springs, and I almost certainly wouldn't have discovered Dystopian Wars if I hadn't seen it at Eagle and Empire in Alexandria (and thereby might not have ever gotten into Spartan's other products--Firestorm Armada, Halo Fleet Battles, and Halo Ground Command).
So, at my FLGS (in the various places I've lived), I have:
-found new opponents
-played in friendly tournaments
-been provided a place to play (don't really have anywhere to play miniatures games at my house)
-had discussions about painting, terrain building, modeling, army composition, gaming, movies, books, etc with both other gamers and the game staff
-discovered new games, models, rulebooks, terrain, expansions, etc
I've had a mix of finding what I needed on the shelf and having to have it ordered, but almost all of my ordering experiences have been positive, and I'm a pretty patient gamer so I've never needed something immediately.
To me, a good FLGS is an important part of the tabletop gaming experience, for all the reasons I listed above. Other people's mileage may vary, depending on your tastes.