I've lost count as well - ish.
At a rough guess, I would say, 3 or 4 sets of OCZ Flex XLC D9, 4 sets of Team Xtreem 9600 D9 and 8 or 9 sets of Ballistix/Tracers all dead.
The
odd thing is, I removed the heat spreaders on the last set when they were brand new and they have lasted for over 6 months with lots of torture and no death so far, and yes, they are D9!