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