The Incoming CD was bundled with the computer, and so I played that a lot. Encarta also had a game in which you wandered a castle and had to answer history questions to go further or something like that.
Also, Internet Explorer 4, Winamp 2, RealPlayer G2, dialers for the first free dial-up ISPs which displayed skyscraper-sized banners at the bottom of the screen but saved you from paying 9.90 USD for Internet access, timer programs to control the usage of said Internet access (you still had to pay the phone company, see), McAfee Antivirus '99, Kazaa, eMule 0.2something, Cacheman/Cablenut and a ton of other "tweaking" apps, GetRight, CloneCD 2, Winzip, Hacha (a Spanish app to split files in 1.44 MB segments), ACDSee 3, etc.