Classic Mac OS was buggy by design - it didn't have multitasking and memory protection, it was single user... Windows had that same problem before 2000 (well, NT 4, but not many people used that).
I use OS X daily and I use Windows 7 daily. I have far fewer issues with OS X for whatever reason that may be. My computers don't magically reboot or bluescreen nearly as much. It might happen every 6 months at the most, where with Windows it probably happens every 2 months.