We tried a meat loaf in the crock pot a couple of months ago and have made it several times since. The link I am posting for the recipe is for double the amount I make for two of us. The quantities listed below make enough for two meals for two. You need:
1 lb of lean ground beef
1/2 C of milk
1/2 C of dry bread crumbs
1 envelope of dry onion soup mix
First combine the eggs, milk, bread crumbs, and soup mix and mix together. Then add the meat. Mix thoroughly, then shape into a rectangle or oval that won't touch sides of crock pot. Cook on low for 6 hours.
We like mushrooms with ours, so at about 6 hours I add some in and let it cook for another hour or so. Another variation Michael adds is some red wine mixed in with the beef and some basil on the top of the loaf before cooking.
I forgot to take any prep pictures, so this is after cooking for most of the day before I added in the mushrooms. I realize the pictures of this meat loaf look sick...but I promise it tastes really good!
For our second meal with this we usually have it on sandwiches which is also really good.
Here is the link for the recipe: http://www.food.com/recipe/crock-pot-meatloaf-184426
You can easily adjust the serving amount on the recipe link to fit the quantity of servings you need.