Clunking mystery

So I just left an auto shop, where I finally-after 2 years- , asked them to try to figure out what the clunking/thud noise is when I go over bumps. no success. Ive read a bunch of forums and everybody seems to be having this mysterious issue with no solutions found so far. Ive had my front sway bar/links and bushings replaced, got brand new tires, and the mechanics say my shocks, struts and mounts are fine. Help! Nobody seems to be having any other ideas. It seems to be coming from my drivers (left) front end. Before I got all the tires replaced, that tire was also cupped pretty badly. But the mechanics say that couldve been due to poor alignment, which I also got fixed.