I've had my N800 for over a year now, no crashes after the first OS upgrade (the original OS version had a problem where occasionally a watchdog timer would see the DSP not responding, and auto-reboot the N800. Only happened when it was idle though, e.g. at night. Technically this wasn't actually a crash, it just looked like one until you learned the cause of it).

MicroB (mostly) and Opera (sometimes) have occasionally unexpectedly shut down. But it's been a year, and the number of browser crashes less than a handful. Not bad at all really. The metalayer-crawler sucked my battery dry on two occasions a few months back (after that I disabled it and nothing like that has happened again).

My N800 has been and continues to be a superb companion.