All of my original friends came from the Halloween "Add Me" thread and, not surprisingly, they fizzled out soon after adding. I've found a handful of great neighbors here on the forums, and have spend the last few weeks weeding out non-players and adding people from my neighbor request queue.
I have a list of probably 15-20 people that don't visit that I'll be deleting if they don't pick up when the Christmas update hits. Once that happens I'll probably again turn to the forums to find friends -- the success rate of PMd friends is much higher than randoms.
Good luck to you! I too play multiple times every single day, and visit all my neighbors daily, so it's rough when people don't visit in return. Hope you find some good'ns! :wink: