Just off the top of my head...

G1 Inferno and Hot Spot had snapped ladders. Inferno also had a tab which holds his arm to the base of the ladder in vehicle mode snapped off.
G1 Prowl had taken a lot of punishment: broken roof/front windscreen, broken rear windscreen/shins, right arm snapped off at the shoulder. I possibly snapped the waist swivel, too - can't really remember.
G1 Silverbolt - broken hip hinge.
G2 Slag - gun handle snapped off.
G1 Optimus - rifle snapped in two, broken smokestack, leg snapped off, broken trailer door hinge, trailer drone support arm snapped off at the hinge.