Windows ME was my most disliked OS (too buggy, even after service packs). I think the level of complexity finally hit the wall given the 9x series lack of good memory&#x2F;file protections.<p>My favorite 9x OS is 98 SE (which was a stand-alone release, not a service pack). But 98 &quot;first edition&quot; did add substantial features to 95: IE 4, multi-monitor support, sfc was added (which was useful because 9x got corrupted a LOT), ACPI support, better plug and play, and better hardware support overall.<p>98 SE just added USB support out of the box (which was a big deal for those of us trying to use USB mice), IE 5, WebDAV, Windows Explorer improvements, ICS, improved WMP, and all of 98 &quot;first editions&quot; hotfixes and updates. You could make 98 &quot;first edition&quot; into 98 SE more or less, but 98 SE was a nice thing to &quot;just install&quot; and have everything work.<p>My 1990s&#x2F;early 2000s OSs looked like this: 3.1, 95, 98, 98 SE, ME, back to 98 SE, and then 2000, XP SP1, and beyond. Skipped XP pre-SP1 as it was a pretty shoddy release compared to 2000 at the time, and ran away from ME screaming.