(This one is soooo good and it doesn't get much easier than this)
4 cups beef cubes
10 3/4 can cream of mushroom soup
1 cup sour cream
put beef in crock pot.
Cover with mushroom soup.
Cover and cook on low 8 hours or high 5 hours.
Before serving stir in sour cream. Serve over noodles or rice.
(I don't like mushrooms, but I'm sure you could use cream of celery or something instead.)