One reason they might be so good is that they are definitely not meant for the vegetarians out there. This dish is a meat eater's delight! Start by frying up together 1# ground beef and 1/2# bacon that's been cut into pieces. By cooking together, the bacon gets cooked but not crispy.
In a casserole or oven-proof dish put the cooked meat and add the beans. I use 2 cans of pork & beans including the liquid. Then I use 3 other varieties, usually butter beans, black beans, and kidney beans -- but you need to drain the liquid from these cans before adding them.
The only other ingredients you need are 1 C. ketchup and 1/2 C. brown sugar. Mix all the ingredients together. Cover and bake in 325 oven for at least one hour, but longer is okay too.