They are WAY better if you vacuum seal them first- they last longer that way, too. Every kitchen ought have a good vacuum sealer in it. Also, you can cut down on the flaccidity (yay, new word, I looked it up!) if you don't overpack the bag- the faster they freeze, the firmer they will be, and the less the frost crystals will damage them. I first place them on a stainless steel rack so they are not touching each other, then place the rack in the freezer for a few hours. After that, arrange them in a vacuum bag so they are one layer, vacuum, and throw them back in the freezer. You want to do this in a hot hurry so that they don't thaw out! This method will work with any veggies.
I think I learned this on that Alton Brown show.