My 9700/9780 were bulletproof, the 9800 is very delicate! I've had to replace the faceplate buttons that peeled off and the slider has gotten very loose.
The 8700 was the best. I had one that spent the better part of a day at the bottom of a pool. I brought that little beast back to life about a year later when I was looking for a project to do. Had to replace the mic due to contact corrosion (and I replaced the housing seeing as I had torn it down already) but that was it. Took a little bit to get a PC to recognize it to reload the OS.
While knowing that BB's are built like water-proof tanks, I still baby mine and have NEVER dropped it... Always carry it in a case, in my front pocket and hold it tightly when I'm using it.
My wife's BB though... I can't imagine the torment it has gone through... If I was her BB, I'll be suing her for abuse... But still, it still putters along like how a water-proof tank should.