Snickers, Mars Bars, M&M's (all varieties), Reeses Pieces, Kraft Caramels, Butterfinger, Goldenberg's Peanut Chews, and GooGoo Clusters.   It's really hard to have one favorite.

And a few that I'm not sure they still make: Chunky, Zagnut, and Clark Bars.

And Mallomars, which may actually be a cookie.