Hmmmm......folded two Foes LTS 16 frames, snapped a Spooky Project X (the swing arm tube that supported the shock mount area), cracked chainstays on early Intense M1.
Since the middle-to-late 90's I don't think I've had any issues with anything else.
This 2002 Cannondale CAAD5 came across my bench recently.
Fantastically light (1400g for a 58cm road frame), but no wonder it cracked:
Really poor dropout design. Stamped from 1/4" plate, sharp edges with a major x-section change and hardly any vertical thickness. That short section, only 60mm², has to take all the stress and strain when welded to those stiff, fat, round chainstays.
If only they'd stuck with the simpler dropout from the CAAD3 series and not been tempted to save around 3g of aluminium
For the repair, I made up a plug for the cutout, U-cut the crack, Welded up, filed to surface, and back on the road.