+1 for Larabars. I'm pretty pleased that they're more widely available these days. Last summer, I had a organic farmer who had a shop out in Illinois somewhere and stocked them have him bring me a stash once every two weeks to the weekly Farmers Market. He was great.
But now I can get them at Trader Joe's or Whole Foods (though TJ's has all the flavours I don't like).
Clife bars are decent -- they've done me well on rides but a little too... thick. In the dead of summer, it's tough trying to keep that down.