Our easy go-to is Goulash, or what some people have called goulash. It's just a ground beef tomato casserole.
Brown the beef. Cook Egg noodles. Combine Egg noodles,and beef with plain old tomato sauce from the can, a bunch of shredded cheddar cheese, canned corn (drained) and whole olives (drained). Put some extra cheese on top if you want. It's simple and delicious. Anytime we've tried to change it up (add onions! Use different cheese!) it just ruins it.
We also do the Tater Tot casserole (or cowboy casserole), pretty much the same way except corn not peas.
Taco salad- brown the ground beef with taco seasoning- mix with chopped lettuce, tomato, can of kidney beans or whatever kind, avocado, grated cheese. sliced olives. Coat the whole thing in a mixture of jar salsa and 1,000 Island dressing (1/2 and 1/2). Serve it up with Fritos. Thats how we like it. Yum, I'll be making that next week.
I also have an easy skillet taco/cornbread bake I do... Brown the ground beef, throw in a can of black beans, can of corn (drain all these), a jar of salsa. simmer that for about 10 or 15 minutes. Then mix up your favorite, instant cornbread. Put grated cheese on top of the bean/meat mixture, then spread the cornbread batter over it and bake til the cornbread is done. You have to have an oven safe skillet for this.
OK one more, Mexican Lasagne, a little more complicated but some people really like it. Brown the ground beef and add taco seasoning, a little Lawry's salt, can of green chilies, and can of diced tomatoes. Simmer 15-30 minutes. It may also have a small can of tomato sauce in it, I don't have the recipe in front of me. Mix 8 oz of ricotta with an egg. Grate up some monterey jack cheese. Then layer this stuff with corn tortillas like a lasagne. Build up from the bottom---meat mixture, tortillas, ricotta mixture, cheese, then repeat ending with cheese on top. Bake it up for 1/2 hour.
Sorry I didn't write these as real recipes with the ingredients listed first. If you like them you can translate them. And I also didn't put any exact measurements or oven degrees. I am assuming you are a decent cook and can figure it out! None of these are too hard to screw up.