Maybe not the most bugs but one of the most memorable bugs/glitches I found was way way way back in the Battlefield 3 Beta. There was a glitch where occasionally when you revived someone as medic, your character model froze went into a T-Pose (Think "Christ the Redeemer" but with defribs) and you would just float around like that, until you died. Of course that beta also had the famous extended neck glitch for the support class. Good times.
Second Liuetenant Kyle Kirch
193rd Glider Infantry Regiment.
Charlie Company, First Platoon.