The worst turbulence and then wind shear I ever experienced was a bmi flight LHR -MAN in an 80 mph gale. Basically it was like the plane was grabbed by a giant hand and moved in every direction possible. Still got down to over the runway before we went around. Even on the 2nd try it was almost a repeat but it seemed to calm and the pilot just slammed it down and like the woman behind me said "never been so glad to get off a plane before". The first try was probably in much worse conditions than the infamous Lufthansa landing attempt at Hamburg but the bmi pilot was much smarter and went around. I remember a very rough flight on a BOAC VC-10 over the North Atlantic which was surprising since it was normally such a smooth flight on those aircraft.