With later hardware and software, especially G3/G4 with Mac OS 9.x, the machine crashed less often, but usually still did at least a few times per week.
I recall having unexpected reboots every few days (except on systems with complicated SCSI chains, what a nightmare), but my bar for system extensions was also unreasonably high. I remember feeling a little sick seeing multiple rows of extensions when friends restarted their Macs.
This exact combo, plus MacSSH, Ircle and SoundJam, for years.
As another respondent also remembered it, I would probably get less than one crash a day. Windows 95 had it's own (multifarious) problems. I was maintaining servers with years of uptime and definitely looking forward to OSX. :)