I used the wear those, too, but have found that the CW-X knickers/tights are much better. I have the expert knickers for cold weather running (even wore them in a sprint tri) and feel they really hold the muscles together. They are kinda pricey, but worth it.

The trick is to get a a size that is a performance fit (i.e. a little too snug for couch-lounging) rather than a comfort-fit. You might try a search for CW-X in this thread, as a number of gals here use 'em.