3 stickies for Win/Mac/Linux would suffice imho. That's about 99.9% ish of the installed based OS clients in the world anyway.
Also, not a hell of a lot is needed for the majority of everyday tasks really.
Here's what I have on the netbook
WinRAR, ImageGrabber, VLC, MPC-Home Cinema, AutoGK, VirtualDub, DVD Decrypter, DVD Shrink, IrfanView, Revo Uninstaller, JDownloader, Shareaza, utorrent & Flock browser. 