I have a busted R2 on one of my two Dualshocks. Motorstorm is interesting because the R2 always reads that it's being held down even though it's not, so the boost just continuously gets used up until my vehicle explodes. I'm fairly sure it happened due to mistreatment from the previous owner though, so I have no complaints.
I thought this was going to be about the design choice of the triggers themselves, which would have been a far more interesting topic. Although it's probably been done in the past.