While there was much excitement & media hype to the Win95 launch, Windows 3.1 (1992) is definitely a better candidate for this list--it had all the foundations including advanced font support, multimedia, mouse access, networking (Windows for Workgroups) and even 32-bit application support (Win32s)--all for personal consumers. By 1995, everyone who was buying Win95 already had Win3.1 (except DOS-only holdouts) and even the DOS-only folks were using their mice to interact with their PCs. (I would argue for Windows 3.0 over 3.1, but 1991 was his starting point...)
To add, I'd say that Microsoft Office would have been a better choice than the Apple Newton. Around 1992-1994 was when companies dropped, en masse, their DOS-based WordPerfect, Lotus 1-2-3, and Harvard Graphics installations for Word, Excel, and PowerPoint. So why does that count for "personal" uses? Because now, MANY households, almost all students (including those on Macs), and almost all businesses use it. Home users used to pirate copies of Office, and Microsoft now gives it away for less than $150 for non-commercial use. Back in the '90s, Microsoft was trying to foist Microsoft Works on consumers, with Office having a $400+ price point. Word and Excel file formats are ubiquitous now... (And while I applaud & appreciate "office" FOSS, they only exist because of MS-Office's successes & intentionally maintain compatibility with MS-Office file formats).
