I hung on to 98 until 2001 for gaming, but at that point most stuff worked perfectly on 2k. While it wasn't intended for "home" users, 2k was the preferred OS among my group of friends until XPsp2 or so.
I really don't get why the NT kernel wasn't introduced to the "home" market until XP.
There was also a companion "Windows 2000 Home" edition announced, however it was rolled into XP while Windows ME was released as largely unwanted stopgap.
Now, despite the lingering snarkiness from the *nix-hipsters, Windows is incredibly robust... even more so today since in Vista and on even the graphics driver can crash without an OS restart in most cases.
(It doesn't matter who's first. It matters who gets it into the hands of double-digit millions of end-user CPUs.)
[Edit: I was replying to a "But, but, BeOS had protected memory first!" comment.]
I know Jeff is looking at this more on the design side than the technical, but I'd argue that Windows XP was a much bigger deal than Windows 95, being the first consumer release based on the NT kernel and thus the first "home" version of Windows with reasonable memory protection between processes. How quickly we forget how terrible Windows was in the bad old days of daily BSODs.