NT4 had many serious BSODs. SP6 was so problematic due to a critical bug in LSA that it was re-released as SP6a.

Windows bugs have moved more and more into the 'edge case' territory. Not that major issues don't crop up for "everyone" today, but BSODs used to be much more common. Part of that was due to the architecture, thus drivers, but the other side of it was core Windows functionality that just had bugs.