I like to buy a bunch of ground beef and cook it up, then freeze it in meal size portions.
You still have some cooking to do, but that is one task that is done. You can use the ground beef in casseroles, lasagna, soups, sloppy joes, tacos, things like that.
I also buy several chickens (or lots of chicken breast) and cook up, then dice and freeze in meal size containers. (I also do this with turkey at the holidays.) This is handy for pasta salads, casseroles, chicken and dumplings, lots of stuff! You can also freeze the chicken broth that you make (I boil the chickens, unless it is chicken breast... that I saute'.)... I freeze it in 2 cup containers, or freezer bags. If you use freezer bags for the chicken broth, they sometimes leak when in the microwave, so put them in a bowl when you thaw them.