My perfect jean is Gloria Vanderbilt's Amanda line. If I'm buying new, I go to Kohl's, but I usually check my local Goodwill stores first. My day job is kinda brutal on clothes so I have no qualms about buying thrift for that.
Haven't bought a new pair of jeans since I can't remember when. All my jeans come from thrift stores, partly because it's way less expensive but also because they're already washed so there's no worry about shrinkage and they're soft and broken in.