I can only wear low cut jeans because I have WIDE hips and a small waist (apparently I was built for child-bearing!
) so any jeans that fit my gigantic hips are massively too big above my hips. So, I was forever dealing with "butt crack syndrome" - Old Navy, GAP, American Eagle, and Bluenotes all were always slipping down and showing off my crack. Long shirts were my friend.
A couple months ago, someone posted on the Budget Board that Lucky Brand Jeans were $27 on target.com (regularly $110). I scooped up two pairs to meet the $50 free shipping... I have not put on another pair of jeans since. They have a bit of stretch to them and the denim just feels more comfortable than any other jeans I've ever tried. Because they move with you more than other jeans, they don't fall off when you bend over or crouch down! I'm a convert!