Let me see now,

Gimp for Tiger is good (and free), very powerful image manipulation - search for GIMP-2.6.6-Tiger-universal.dmg

Burn is a great free CD/DVD burner

Caffeine for disabling the screensaver

Camino is also a very good free browser, in my opinion works faster than TenFourFox

Carbon Copy Cloner for backing up to and booting from an external hard drive - version 3.4.7 is the latest for Tiger

Handbrake 0.9.1 for video conversion

I find Image Tricks a good quick photo editor

Meteorologist 1.5.6 for weather in your dock

Onyx 1.8.5 for system maintenance

Stuffit Expander for all archive zips / rars etc.

VLC media player 0.9.10

Lastly, Perian to allow playing of Windows media files

That's all I can find on my Tiger that you don't need to pay for ...

Cheers

Hugh