If you're focused on just getting strong and not weightlifting, then you need three movements: squat, pull, press. Those categories include back/front squats, deadlifting (conventional, SLDL, RDL), and pressing (standing strict, push, maybe incline). The only other thing I would throw in there are good mornings. I've been told good mornings are to developing squats as RDLs are to developing pulling power.
Hope that helps,
Javier A. Sanjuan
Olympus Barbell Club
Dear God, please help me lift heavy and be awesome. Thanks. Amen.