Every now and again, you might stumble upon a sale on meat or other perishable items at your grocery store. Or maybe you only shop for groceries once a month. In either case, you're going to have to stash all that food somewhere.
For packaged foods that can be easily stacked, a chest freezer is a good choice: It offers better energy efficiency and more space than an upright freezer.
On the other hand, if you're frequently storing food that can't be crushed, or would like to easily spot what items you've loaded without having to dig around, an upright freezer would be a more worthwhile purchase.