Sloppy Joe's (usually with Tater tot's and "something green"--brocolli, green beans, salad)
Meatloaf (usually with baked potatoes and "something green") for fun do mini meatloaves in muffin tins
Homemade Pizza! You can make pizza crust from scratch, or use a mix, or pillsbury or boboli crusts, or use tortillas or english muffins. Home Made Pizza is a fun friday night supper. Getting kids to top their own pizzas is a good way to get them started in the kitchen. AND home made pizza is an AWESOME way to use up leftovers! leftover Taco stuff can be used on Taco Pizza. Sloppy Joe pizza is great (leftover Sloppy Joes and co-jack) Leftover beef, pork, chicken or turkey can be shredded and mixed with BBQ sauce for BBQ pizza)
For more ideas two of my favorite blogs are http://www.5dollardinners.com/ and http://www.lynnskitchenadventures.com/ Lynn just started a series of ground beef recipes-- not only are her recipes good, but there have been some awesome ideas in the comments too!
ETA-- Oh, don't forget "breakfast for supper" for a fun change!