The Luna bars are a little less dense and less caloric than the Cliff Bars. Some of them are quite good, I'm into the Sesame Raisin ones now, no chocolate or yogurt layer to melt while in your pocket.
I've also found that a before ride snack of something like a little peanut butter spread on half a whole wheat wrap with a banana keeps me from getting hungry for a long time. I usually save the Luna bar for after, as I've also read that one needs food for recovery.