I love beans and eat them pretty frequently. One dish I make often is one I created back when I was a poor teenage vegetarian. I now eat meat, but I still eat this dish. Warning: This will sound gross to some people and it sure ain't a pretty dish to look at, but if you like vinegar it's really good!
First, over medium heat I saute one medium onion and about 4 cloves of garlic in some olive oil. I salt it and let it cook for about 5 minutes.
Then I add a can of black beans. I drain out most, but not all, of the liquid from the can first. I heat it for a minute or so, then I sprinkle a layer of oregano across the entire surface of the beans.
I then pour in enough balsamic vinegar to cover the beans. I let it simmer until the balsamic cooks down and the beans are no longer watery but have a vinegary glaze.
Often I eat it just like that, but sometimes I also mix in about half an avocado at the end. I then chop up the rest of the avocado and eat some raw slices with the hot beans.
I know this sounds horrendous, but really, it's good if you love vinegar and it's really cheap!