I need a good juicy pot roast recipe - how do you get that killer flavor?

I've done it on stove top with high end cookware, in a crock pot and in the oven. Crock pot seems to be the easiest. It is good with the vegetables and everthing else mixed in. Always comes out eat-with-a-fork juicy. But I can't seem to get that killer flavor that I've had in a few wonderful homes and home-style restaurants. Is it beef stock I'm missing? Some magical seasoning that southerners hide from yankees? I always get a good cut of meat and cook it slow.