Shareware stuff

TUCOWS

Great collection of internet related software for Win3.x/95/NT and Java

Winfiles

All stuff for Win95/NT

Gamecenter

For all you gamers out there

SHAREWARE.COM

Stuff for everything

Linux stuff

Don't know too much about it but from what I've tried, I like it.  For you developpers Sybase, Informix, InPrise, and Oracle are giving their databases for free under this hot platform.

Redhat

Up to version 5.2 right now that you can download.

S.U.S.E

The most comprehensive Linux package according to PC Plus Magazine

Caldera

Linux for businesses.  They also do OpenDOS.