We've always frozen corn on the cob one of two ways. The easiest is just to pull the ears and throw in the freezer shucks and all, no bag or anything. Usually though to save space and keep the freezer cleaner we just shuck and silk the corn, clip the silk end to make the ears short enough to fit into the bags, then place in zip-lock freezer bags and straight into the freezer. We've never blanched or cooked first.
If we are planning on cooking it on the grill we take it from the freezer and let it thaw a day in the 'fridge. Otherwise we just rinse it and put it in boiling water straight from the freezer.
We eat almost all field corn though, we hardly ever plant sweet corn. Not sure if that matters in how well it keeps this way.