I really would try to get the front end off the ground and get someone to turn the wheel back and forth at full rotation in addition to jerking movement left and right.
With the wheel off the ground you can really tell a lot, especially the ball joint which can't really be diagnosed accurately unless the wheel is off the ground unless it is really bad. I myself am leaning towards ball joints as they are the weakest link in our suspension system and cause a myriad of problems if not replaced.
Good luck,
Adam